JP7445411B2 - Photoelectric conversion element and organic sensor and electronic device including the same - Google Patents

Description

The present invention relates to a photoelectric conversion element, and particularly to a photoelectric conversion element that can improve charge extraction efficiency, and an organic sensor and electronic device including the same.

A photoelectric conversion element is an element that receives light and converts it into an electrical signal, and includes a photodiode, a phototransistor, and the like, and can be applied to an organic sensor, a photodetector, a solar cell, and the like.
Organic sensors are required to have higher resolution day by day, and as a result, the size of pixels is becoming smaller.

Currently, silicon photodiodes, which are mainly used, have a problem in that as the size of the pixel decreases, the absorption area decreases, resulting in a decrease in sensitivity.
As a result, in recent years, research has been conducted into organic materials that can replace silicon.
Organic materials have a large extinction coefficient and can selectively absorb light in a specific wavelength range depending on their molecular structure, so they can simultaneously replace photodiodes and color filters, which is advantageous for high integration.

However, organic materials may exhibit different properties from silicon due to their high binding energy and recombination behavior, making it difficult to accurately predict the properties of organic materials, making it difficult to predict the properties of organic materials. There is a problem in that it is difficult to easily control the required physical properties.

Japanese Patent Application Publication No. 2014-17321

The present invention has been made in view of the problems with the conventional organic photoelectric conversion elements described above, and an object of the present invention is to provide a photoelectric conversion element that can improve charge extraction efficiency.
Another object of the present invention is to provide an organic sensor including the photoelectric conversion element and an electronic device including the photoelectric conversion element.

A photoelectric conversion element according to the present invention, which has been made to achieve the above object, includes a first electrode and a second electrode facing each other, and a photoelectric conversion element disposed between the first electrode and the second electrode, a photoelectric conversion layer that absorbs light in a region and converts it into an electrical signal; and an inorganic nanolayer containing a lanthanum group element and disposed between the first electrode and the photoelectric conversion layer, The group element is characterized by containing ytterbium (Yb) .

Preferably, the inorganic nanolayer is in contact with the first electrode.
Preferably, one surface of the inorganic nanolayer is in contact with the first electrode, and the other surface of the inorganic nanolayer is in contact with the photoelectric conversion layer.
Preferably, the first electrode is a transparent electrode with a light transmittance of about 80% or more, or a reflective electrode with a light transmittance of less than about 10%.
Preferably, the transparent electrode includes at least one of an oxide conductor and a carbon conductor.
Preferably, the thickness of the inorganic nanolayer is about 5 nm or less.
Preferably, the thickness of the inorganic nanolayer is about 2 nm or less.
Preferably, the first electrode is a cathode and the second electrode is an anode.

Further, the photoelectric conversion element according to the present invention, which has been made to achieve the above object, includes a first electrode including a transparent conductor having a light transmittance of 80% or more or a reflective conductor having a light transmittance of less than 10%; The photoelectric conversion layer includes a photoelectric conversion layer that is placed on the electrode and absorbs light in at least a part of the wavelength range and converts it into an electrical signal, and a second electrode that is placed on the photoelectric conversion layer. The surface of the first electrode facing the conversion layer is covered with an inorganic nanolayer with a thickness of 5 nm or less, and the effective work function on the surface of the first electrode facing the photoelectric conversion layer is determined by the transparent conductor or the The inorganic nanolayer includes an inorganic substance, the inorganic substance includes a lanthanum group element, and the lanthanum group element includes ytterbium (Yb). .

The difference between the work function of the transparent conductor or the reflective conductor and the effective work function at the surface of the first electrode facing the photoelectric conversion layer is preferably 0.5 eV or more.
The work function of the transparent conductor or the reflective conductor is preferably 4.5 eV or more, and the effective work function at the surface of the first electrode facing the photoelectric conversion layer is preferably 4.0 eV or less.
The effective work function at the surface of the first electrode facing the photoelectric conversion layer is preferably 3.0 eV or less.
Preferably, the transparent conductor includes an oxide conductor or a carbon conductor.
Preferably, the inorganic nanolayer has a thickness of about 2 nm or less.
Preferably, the first electrode is a cathode and the second electrode is an anode.

An electronic device according to the present invention made to achieve the above object is characterized by having the above photoelectric conversion element.

An organic sensor according to the present invention made to achieve the above object is characterized by having the above photoelectric conversion element.

Preferably, the organic sensor is an organic CMOS image sensor.

An electronic device according to the present invention made to achieve the above object is characterized by having the above organic sensor.

According to the photoelectric conversion element and the organic sensor and electronic device including the same according to the present invention, charge extraction efficiency of the photoelectric conversion element can be increased by improving charge mobility and reducing residual charge.

1 is a cross-sectional view showing a schematic configuration of a photoelectric conversion element according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a schematic configuration of a photoelectric conversion element according to another embodiment of the present invention. 1 is a cross-sectional view showing a schematic configuration of an organic CMOS image sensor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a schematic configuration of an organic CMOS image sensor according to another embodiment of the present invention. 1 is a plan view schematically showing an organic CMOS image sensor according to an embodiment of the present invention. 6 is a cross-sectional view showing a schematic configuration of the organic CMOS image sensor of FIG. 5. FIG. 6 is a sectional view showing a schematic configuration of another example of the organic CMOS image sensor of FIG. 5. FIG. 6 is a cross-sectional view showing a schematic configuration of still another example of the organic CMOS image sensor of FIG. 5. FIG. 6 is a cross-sectional view showing a schematic configuration of still another example of the organic CMOS image sensor of FIG. 5. FIG. FIG. 7 is a plan view schematically illustrating an organic CMOS image sensor according to still another embodiment of the present invention. 11 is a cross-sectional view showing an example of a schematic configuration of the organic CMOS image sensor shown in FIG. 10. FIG. 11 is a cross-sectional view showing another example of the schematic configuration of the organic CMOS image sensor shown in FIG. 10. FIG. FIG. 7 is a plan view schematically illustrating an organic CMOS image sensor according to still another embodiment of the present invention. 14 is a cross-sectional view showing an example of a schematic configuration of the organic CMOS image sensor shown in FIG. 13. FIG. FIG. 2 is a cross-sectional view showing another example of the schematic configuration of an organic CMOS image sensor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing still another example of the schematic configuration of an organic CMOS image sensor according to an embodiment of the present invention. 1 is a diagram showing a schematic configuration of an electronic device according to an embodiment of the present invention.

Next, specific examples of embodiments of a photoelectric conversion element, an organic sensor including the same, and an electronic device according to the present invention will be described with reference to the drawings.

Hereinafter, embodiments will be described in detail so that those with ordinary knowledge in the relevant technical field can easily implement the embodiments.
However, the actually applied structure can be realized in various different forms and is not limited to the embodiments described here.
In the drawings, the thickness of layers and regions are exaggerated for clarity.
When we say that a layer, membrane, region, plate, etc. is ``above'' another part, we mean not only when it is ``directly on top'' of another part, but also when there are other parts in between. Also included. Conversely, when one part is said to be ``directly above'' another part, it means that there are no other parts in between.

Unless otherwise defined below, "substituted" means that a hydrogen atom in a compound is substituted with a halogen atom, hydroxy group, alkoxy group, nitro group, cyano group, amino group, azide group, amidino group, or hydrazino group. , hydrazono group, carbonyl group, carbamoyl group, thiol group, ester group, carboxyl group or its salt, sulfonic acid group or its salt, phosphoric acid or its salt, silyl group, C1 to C20 alkyl group, C2 to C20 alkenyl group, C2-C20 alkynyl group, C6-C30 aryl group, C7-C30 arylalkyl group, C1-C30 alkoxy group, C1-C20 heteroalkyl group, C3-C20 heteroaryl group, C3-C20 heteroarylalkyl group, C3-C30 It means a group substituted with a substituent selected from a cycloalkyl group, a C3-C15 cycloalkenyl group, a C6-C15 cycloalkynyl group, a C3-C30 heterocycloalkyl group, and a combination thereof.

Unless otherwise defined below, "hetero" means containing 1 to 4 heteroatoms selected from N, O, S, Se, Te, Si, and P.
Hereinafter, the term "combination" includes a mixture and a laminated structure of two or more.
In the following, "metal" includes metals, metalloids or combinations thereof.
In the following, "energy level" refers to the highest occupied molecular orbital (HOMO) energy level or the lowest unoccupied molecular orbital (LUMO) energy level. There is.

In the following, the value of a work function or energy level is expressed as an absolute value from a vacuum level.
In addition, when the work function or energy level is deep, high, or large, it means that the absolute value is large when the vacuum level is "0 eV", and when the work function or energy level is shallow, low, or small, it means that the vacuum level is "0 eV" and the absolute value is large. Setting the level to "0 eV" means that the absolute value is small.
A photoelectric conversion element according to an embodiment of the present invention will be described below.

FIG. 1 is a cross-sectional view showing a schematic configuration of a photoelectric conversion element according to an embodiment of the present invention.
Referring to FIG. 1, a photoelectric conversion device 100 according to an embodiment of the present invention includes a first electrode 10, a second electrode 20, a photoelectric conversion layer 30, and an inorganic nanolayer 40.
The substrate (not shown) may be placed on the first electrode 10 side or on the second electrode 20 side.

The substrate is made of, for example, an inorganic material such as glass, an organic material such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyethersulfone, or a combination thereof, or a silicon wafer.
The substrate can also be omitted.

The first electrode 10 and the second electrode 20 are opposed to each other.
One of the first electrode 10 and the second electrode 20 is an anode, and the other one is a cathode.
For example, first electrode 10 may be a cathode and second electrode 20 may be an anode.
As an example, the first electrode 10 is an anode and the second electrode 20 is a cathode.
As an example, the first electrode 10 is a cathode and the second electrode 20 is an anode.

At least one of the first electrode 10 and the second electrode 20 may be a transparent electrode.
Here, the transparent electrode may be a transparent electrode having a high light transmittance of about 80% or more, and may not include, for example, a translucent electrode for a microcavity.
The transparent electrode may include, for example, at least one of an oxide conductor and a carbon conductor, and the oxide conductor may include, for example, indium tin oxide (ITO), indium zinc oxide, oxide: IZO), zinc tin oxide (ZTO), aluminum tin oxide (AlTO), and aluminum zinc oxide (AZO). The carbon conductor may be one or more selected from graphene and carbon nanomaterials.

One of the first electrode 10 and the second electrode 20 may be a reflective electrode.
Here, the reflective electrode may be a reflective electrode having a light transmittance of less than about 10% or a high reflectance of about 5% or more, for example.
The reflective electrode may include a reflective conductor such as a metal, such as aluminum (Al), silver (Ag), gold (Au), or an alloy thereof.
For example, the first electrode 10 may be a transparent electrode with a light transmittance of 80% or more, or a reflective electrode with a light transmittance of less than about 10%.

The photoelectric conversion layer 30 is arranged between the first electrode 10 and the second electrode 20.
The photoelectric conversion layer 30 absorbs at least part of the light in the wavelength range and converts it into an electrical signal, for example, light in the green wavelength range (hereinafter referred to as "green light"), light in the blue wavelength range (hereinafter referred to as " A portion of light in the red wavelength region (hereinafter referred to as "red light"), and light in the infrared wavelength region (hereinafter referred to as "infrared light") is converted into electrical signals.
For example, the photoelectric conversion layer 30 selectively absorbs any one of green light, blue light, red light, and infrared light.
Here, selectively absorbing any one of green light, blue light, red light, and infrared light means that the peak absorption wavelength (λ _max ) of the absorption spectrum is approximately 500 to 600 nm, approximately 380 nm or more. It exists in any one of less than 500 nm, more than about 600 nm and less than 700 nm, and more than about 700 nm, meaning that the absorption spectrum in the corresponding wavelength range is significantly higher than the absorption spectrum in other wavelength ranges.

In the photoelectric conversion layer 30, at least one p-type semiconductor and at least one n-type semiconductor form a pn junction, and after receiving light from the outside and generating excitons, Separates the generated excitons into holes and electrons.
The p-type semiconductor and the n-type semiconductor may each be a light-absorbing material, and for example, at least one of the p-type semiconductor and the n-type semiconductor may be an organic light-absorbing material.
As an example, at least one of the p-type semiconductor and the n-type semiconductor may be a wavelength-selective light-absorbing material that selectively absorbs light in a predetermined wavelength range, for example, at least one of the p-type semiconductor and the n-type semiconductor. One can be a wavelength selective organic absorbing material.
The p-type semiconductor and the n-type semiconductor have peak absorption wavelengths (λ _max ) that are the same or in different wavelength regions.
As an example, a p-type semiconductor can be an organic material that has a core structure that includes an electron donating moiety, a pi-conjugated linking group, and an electron accepting moiety.

The p-type semiconductor is represented by, for example, the chemical formula 1 shown below, but is not limited thereto.
(Chem.1)
EDG-HA-EAG...Chemical formula 1
In the chemical formula 1 above,
HA can be a C2-C30 heterocyclic group having at least one of S, Se, Te, and Si,
EDG can be an electron donating moiety;
The EAG can be an electronic containment moiety.

上記化学式１Ａにおいて、
Ｘは、Ｓ、Ｓｅ、Ｔｅ、ＳＯ、ＳＯ_２、又はＳｉＲ^ａＲ^ｂであり得、
Ａｒは、置換又は非置換されたＣ６～Ｃ３０アリーレン基、置換又は非置換されたＣ３～Ｃ３０ヘテロ環基又はこれらより選ばれた二つ以上の融合環であり得、
Ａｒ^１ａ及びＡｒ^２ａは、それぞれ独立して置換又は非置換されたＣ６～Ｃ３０アリール基又は置換又は非置換されたＣ３～Ｃ３０ヘテロアリール基であり得、
Ａｒ^１ａ及びＡｒ^２ａは、それぞれ独立して存在するか互いに結合して融合環を形成し得、
Ｒ^１ａ～Ｒ^３ａ、Ｒ^ａ及びＲ^ｂは、それぞれ独立して水素、重水素、置換又は非置換されたＣ１～Ｃ３０アルキル基、置換又は非置換されたＣ６～Ｃ３０アリール基、置換又は非置換されたＣ３～Ｃ３０ヘテロアリール基、置換又は非置換されたＣ１～Ｃ６アルコキシ基、ハロゲン又はシアノ基であり得る。 As an example, a p-type semiconductor represented by Chemical Formula 1 is represented by Chemical Formula 1A shown below.

In the above chemical formula 1A,
X can be S, Se, Te, SO, _SO2 , or SiR ^a R ^b ;
Ar can be a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C3-C30 heterocyclic group, or a fused ring of two or more selected from these,
Ar ^1a and Ar ^2a can each independently be a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C3-C30 heteroaryl group,
Ar ^1a and Ar ^2a may each exist independently or may be combined with each other to form a fused ring,
R ^1a to R ^3a , R ^a and R ^b each independently represent hydrogen, deuterium, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C3-C30 heteroaryl group, substituted or unsubstituted C1-C6 alkoxy group, halogen or cyano group.

As an example, in Chemical Formula 1A, Ar ^1a and Ar ^2a are each independently a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, or a substituted or unsubstituted anthracenyl group. phenanthrenyl group, substituted or unsubstituted pyridinyl group, substituted or unsubstituted pyridazinyl group, substituted or unsubstituted pyrimidinyl group, substituted or unsubstituted pyrazinyl group group, substituted or unsubstituted quinolinyl group, substituted or unsubstituted isoquinolinyl group, substituted or unsubstituted naphthyridinyl group, substituted or unsubstituted cinnolinyl group, Substituted or unsubstituted quinazolinyl group, substituted or unsubstituted phthalazinyl group, substituted or unsubstituted benzotriazinyl group, substituted or unsubstituted pyridopyrazinyl group base , substituted or unsubstituted pyridopyrimidinyl groups, and substituted or unsubstituted pyridopyridazinyl groups.

As an example, Ar ^1a and Ar ^2a of Chemical Formula 1A are fused to each other to form a ring, and Ar ^1a and Ar ^2a are, for example, a single bond, -(CR ^g R ^h ) _n2 - (n2 is 1 or 2), They may be linked with one selected from -O-, -S-, -Se-, -N=, -NR ⁱ -, -SiR ^j R ^k - and -GeR ^l R ^m - to form a ring.
Here, R ^g to R ^m each independently represent hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a substituted or unsubstituted C3 to C30 hetero group. It can be an aryl group, a substituted or unsubstituted C1-C6 alkoxy group, a halogen or a cyano group.

As an example, the p-type semiconductor represented by Chemical Formula 1 is represented by Chemical Formula 1B-1 or 1B-2 shown below.

In the above chemical formula 1B-1 or 1B-2,
X ¹ can be Se, Te, O, S, SO, or SO ₂
Ar ³ may be a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C3-C30 heterocyclic group, or a fused ring of two or more selected from these,
R ¹ to R ³ are each independently hydrogen, deuterium, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C1 to C30 alkoxy group, substituted or unsubstituted C6 to C30 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups, halogens, cyano groups, cyano-containing groups, and combinations thereof,
G is a single bond, -O-, -S-, -Se-, -N=, -(CR ^f R ^g ) _k -, -NR ^h -, -SiR ⁱ R ^j -, -GeR ^k R ^l - , -(C(R ^m )=C(R ⁿ ))-, and SnR ^o R ^p ,
Here, R ^f , R ^g , R ^h , R ⁱ , R ^j , R ^k , R ^l , R ^m , R ⁿ , R ^o and R ^p each independently represent hydrogen, halogen, substituted or unsubstituted may be selected from C1-C10 alkyl groups, substituted or unsubstituted C1-C10 alkoxy groups and substituted or unsubstituted C6-C12 aryl groups,
R ^f and R ^g , R ⁱ and R ^j , R ^k and R ^l , R ^m and R ⁿ and R ^o and R ^p each exist independently or are connected to each other to form a ring,
k can be 1 or 2,
Y ² may be selected from O, S, Se, Te, and C(R ^q )(CN), where R ^q is selected from hydrogen, a cyano group (-CN), and a C1-C10 alkyl group. ,
R ^6a to R ^6d , R ^7a to R ^7d , R16, and R17 are each independently hydrogen, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or may be selected from unsubstituted C3-C30 heteroaryl groups, halogens, cyano groups, cyano-containing groups, and combinations thereof;
R ^6a to R ^6d may each exist independently or two adjacent ones may be connected to each other to form a fused ring;
R ^7a to R ^7d may each exist independently, or two adjacent groups may be connected to each other to form a fused ring.

For example, Ar ³ in Formula 1B-1 or 1B-2 may be benzene, naphthylene, anthracene, thiophene, selenophene, tellurophene, pyridine, pyrimidine, or a fused ring of two or more selected from these.
The n-type semiconductor may be, for example, fullerene or a fullerene derivative, but is not limited thereto.

The photoelectric conversion layer 30 may be an intrinsic layer (I layer) in which a p-type semiconductor and an n-type semiconductor are mixed in a bulk heterojunction.
At this time, the p-type semiconductor and the n-type semiconductor may be mixed at a volume ratio of about 1:9 to 9:1, and within the above range, for example, at a volume ratio of about 2:8 to 8:2. Within the range, for example, in a volume ratio of about 3:7 to 7:3, within said range, for example, in a volume ratio of about 4:6 to 6:4, within said range, for example, about 5:5. can be mixed in a volume ratio of
The photoelectric conversion layer 30 may include a double layer including a p-type layer containing the aforementioned p-type semiconductor and an n-type layer containing the aforementioned n-type semiconductor.
At this time, the thickness ratio of the p-type layer and the n-type layer may be about 1:9 to 9:1, and within the above range, for example, about 2:8 to 8:2, about 3:7 to 7:3, It may be about 4:6 to 6:4 or about 5:5.
The photoelectric conversion layer 30 may further include a p-type layer and/or an n-type layer in addition to the intrinsic layer.
The p-type layer may include the p-type semiconductor described above, and the n-type layer may include the n-type semiconductor described above.
For example, the layers may be included in various combinations such as p-type layer/I layer, I layer/n-type layer, p-type layer/I layer/n-type layer, etc.

The inorganic nanolayer 40 is arranged between the first electrode 10 and the photoelectric conversion layer 30, and is in contact with the first electrode 10, for example.
As an example, one surface of the inorganic nanolayer 40 is in contact with the first electrode 10, and the other surface of the inorganic nanolayer 40 is in contact with the photoelectric conversion layer 30.
The inorganic nanolayer 40 can be a very thin film, a few nanometers thick, such as having a thickness of about 5 nm or less, such as about 3 nm or less, such as about 2 nm or less.
Inorganic nanolayer 40 can have a thickness of, for example, about 1 nm to 5 nm, about 1 nm to 3 nm, about 1 nm to 2 nm.

Inorganic nanolayer 40 may include an inorganic material having a lower work function than first electrode 10 .
For example, the work function of the inorganic nanolayer 40 may be smaller than the work function of the first electrode 10 by about 0.5 eV or more.
For example, the work function of the first electrode 10 may be about 4.5 eV or more, and the work function of the inorganic nanolayer 40 may be about 4.0 eV or less.
For example, the work function of the first electrode 10 can be about 4.5 eV or more, and the work function of the inorganic nanolayer 40 can be about 3.5 eV or less.
For example, the work function of the first electrode 10 may be about 4.5 eV or more, and the work function of the inorganic nanolayer 40 may be about 3.0 eV or less.
For example, the work function of the first electrode 10 can be about 4.5 eV or more, and the work function of the inorganic nanolayer 40 can be about 2.8 eV or less.
For example, the work function of the first electrode 10 may be about 4.5 eV to 5.0 eV, and the work function of the inorganic nanolayer 40 may be about 1.5 eV to 4.0 eV, about 1.5 eV to 3.5 eV, It can be about 1.5 eV to 3.0 eV, about 1.5 eV to 2.8 eV.

Meanwhile, the inorganic nanolayer 40 is made of a material that satisfies the above-mentioned work function and is formed by thermal evaporation.
In this way, since the inorganic nanolayer 40 is formed by thermal evaporation, the photovoltaic conversion layer 30 is prevented from being thermally and physically damaged in the step of forming the inorganic nanolayer 40 and/or in the subsequent process. Deterioration in performance due to deterioration of the conversion layer 30 can be prevented.
Inorganic substances that can satisfy such characteristics may include, for example, lanthanum group elements, calcium (Ca), potassium (K), aluminum (Al), or alloys thereof.
Lanthanum group elements may include, for example, ytterbium (Yb).

As described above, the inorganic nanolayer 40 is in contact with the surface of the first electrode 10 between the first electrode 10 and the photoelectric conversion layer 30, and has a very thin thickness compared to the first electrode 10. obtain.
Thereby, the inorganic nanolayer 40 can play the same role as the surface treatment layer of the first electrode 10 on the surface of the first electrode 10 facing the photoelectric conversion layer 30. The surface of the first electrode 10 may play a role in adjusting the effective work function of the first electrode 10 .
Here, the effective work function may be a work function at an interface between two layers in a structure in which two layers having different electrical properties are in contact with each other.
The effective work function of the first electrode 10 at the interface between the first electrode 10 and the photoelectric conversion layer 30 can be adjusted by the very thin inorganic nanolayer 40 described above, for example, the first electrode 10 and the inorganic nanolayer 40 can be a composite work function.

As an example, the effective work function on the surface of the first electrode 10 facing the photoelectric conversion layer 30 may be different from the work function of the transparent conductor or reflective conductor forming the first electrode 10 due to the influence of the inorganic nanolayer 40. For example, the effective work function on the surface of the first electrode 10 facing the photoelectric conversion layer 30 may be smaller than the work function of the transparent conductor or reflective conductor forming the first electrode 10.
For example, the effective work function on the surface of the first electrode 10 facing the photoelectric conversion layer 30 is the same as the work function of the inorganic nanolayer 40, or the work function of the inorganic nanolayer 40 and the work function of the first electrode 10 are different. It can be an intermediate value.

For example, the difference between the work function of the transparent conductor or reflective conductor forming the first electrode 10 and the effective work function at the surface of the first electrode 10 facing the photoelectric conversion layer 30 may be about 0.5 eV or more.
For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 may be about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 may be about 4.0 eV or less. .
For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 may be about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 may be about 3.5 eV or less.
For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 may be about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 may be about 3.0 eV or less.
For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 may be about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 may be about 2.8 eV or less.
For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 may be approximately 4.5 eV to 5.0 eV, and the effective work function at the surface of the first electrode 10 may be approximately 1.5 eV to 4 eV. .0eV, about 1.5eV to 3.5eV, about 1.5eV to 3.0eV, about 1.5eV to 2.8eV.

By lowering the work function on the surface of the first electrode 10 facing the photoelectric conversion layer 30 in this way, it is easy to extract the charges (for example, electrons) that move from the photoelectric conversion layer 30 to the first electrode 10, thereby reducing the residual charge. (remaining charge carriers) and can exhibit high charge extraction efficiency.

The photoelectric conversion element 100 may further include an antireflection layer (not shown) on one surface of the first electrode 10 or the second electrode 20.
The antireflection layer is disposed on the side where light enters, and can further improve light absorption by lowering the degree of reflection of incident light.
For example, when light is incident on the first electrode 10 side, the antireflection layer may be disposed on one surface of the first electrode 10, and when light is incident on the second electrode 20 side, the antireflection layer may be disposed on the second electrode 20 side. can be placed on one side of the
The antireflection layer may include, for example, a material having a refractive index of about 1.6 to 2.5, and may include, for example, at least one of a metal oxide, a metal sulfide, and an organic material having a refractive index in the range. .

The antireflection layer may be made of, for example, an aluminum-containing oxide, a molybdenum-containing oxide, a tungsten-containing oxide, a vanadium-containing oxide, a rhenium-containing oxide, a niobium-containing oxide, a tantalum-containing oxide, a titanium-containing oxide, a nickel-containing oxide metal oxides such as copper-containing oxides, cobalt-containing oxides, manganese-containing oxides, chromium-containing oxides, tellurium-containing oxides, or combinations thereof, metal sulfides such as zinc sulfide, or amine derivatives. may include, but are not limited to, organic substances such as.

When light enters the photoelectric conversion element 100 from the first electrode 10 or second electrode 20 side, and the photoelectric conversion layer 30 absorbs light in a predetermined wavelength range, excitons are generated inside.
Excitons are separated into holes and electrons in the photoelectric conversion layer 30, and the separated holes move to the anode side, which is one of the first electrode 10 and the second electrode 20, and the separated electrons moves to the cathode side of the other one of the first electrode 10 and the second electrode 20, and a current begins to flow.
Photoelectric conversion elements according to other embodiments of the present invention will be described below.

FIG. 2 is a cross-sectional view showing a schematic configuration of a photoelectric conversion element according to another embodiment of the present invention.
Referring to FIG. 2, a photoelectric conversion device 200 according to an embodiment of the present invention includes a first electrode 10, a second electrode 20, a photoelectric conversion layer 30, and an inorganic nanolayer 40, similar to the embodiments described above.
However, unlike the above-described embodiments, the photoelectric conversion device 200 according to the present embodiment further includes a charge auxiliary layer 45 between the second electrode 20 and the photoelectric conversion layer 30.
The charge auxiliary layer 45 facilitates the movement of charges (for example, holes) separated from the photoelectric conversion layer 30, thereby increasing efficiency.

Charge assist layer 45 may include, for example, organic, inorganic, or inorganic materials.
The organic material may be an organic compound with hole or electronic properties, and the inorganic material may be a metal oxide, such as molybdenum oxide, tungsten oxide, nickel oxide.
The charge auxiliary layer 45 may include, for example, a visible light non-absorbing material that does not substantially absorb light in the visible light range, and may be, for example, a visible light non-absorbing organic material.

As an example, the visible light non-absorbing substance may be a compound represented by the chemical formula 2A or 2B shown below, but is not limited thereto.

In chemical formula 2A or 2B,
M ¹ and M ² are each independently CR ⁿ R ^o , SiR ^p R ^q , NR ^r , O, S, Se, or Te;
Ar ^1b , Ar ^2b , Ar ^3b , and Ar ^4b are each independently a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C3-C30 heteroaryl group,
G ² and G ³ are each independently a single bond, -(CR ^s R ^t ) _n3 -, -O-, -S-, -Se-, -N=, -NR ^u -, -SiR ^v R ^w -, or -GeR ^x R ^y -, where n3 is 1 or 2,
R ³⁰ to R ³⁷ and R ⁿ to R ^y are each independently hydrogen, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C3 -C30 heterocyclic group, substituted or unsubstituted C1-C6 alkoxy group, halogen or cyano group.

As an example, the visible light non-absorbing substance may be a compound represented by the chemical formula 2A-1 or 2B-1 shown below, but is not limited thereto.

In chemical formula 2A-1 or 2B-1,
M ¹ , M ² , G ² , G ³ , R ³⁰ to R ³⁷ are as described above,
R ³⁸ to R ⁴⁵ are each independently hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, It can be a substituted or unsubstituted C1-C6 alkoxy group, halogen or cyano group.

化学式２Ａ－１ａ又は２Ｂ－１ａにおいて、Ｒ^３８～Ｒ^４５及びＲ^ｏ及びＲ^ｎは、前述したとおりである。 As an example, the visible light non-absorbing substance may be a compound represented by the chemical formula 2A-1a or 2B-1a shown below, but is not limited thereto.

In Chemical Formula 2A-1a or 2B-1a, R ³⁸ to R ⁴⁵ and R ^o and R ⁿ are as described above.

The photoelectric conversion elements (100, 200) described above can be applied to various electronic devices, such as solar cells, organic sensors, photodetectors, and optical sensors, but are not limited thereto.
The photoelectric conversion element (100, 200) can be applied to, for example, an organic sensor, and can be applied to, for example, an image sensor that is an example of an organic sensor.
Hereinafter, an example of an image sensor to which the above-described photoelectric conversion element is applied will be described with reference to the drawings.
Here, an organic CMOS image sensor will be described as an example of an image sensor.

FIG. 3 is a sectional view showing a schematic configuration of an organic CMOS image sensor according to an embodiment of the present invention.
Referring to FIG. 3, an image sensor 300 according to an embodiment of the present invention includes a semiconductor substrate 110, an insulating layer 80, a photoelectric conversion element 100, and a color filter layer 70.

The semiconductor substrate 110 may be a silicon substrate, with a transfer transistor (not shown) and a charge storage 55 integrated therein.
A transfer transistor and/or charge storage 55 is integrated for each pixel.
Charge storage 55 is electrically connected to photoelectric conversion element 100.
Metal wiring (not shown) and pads (not shown) are also formed on the semiconductor substrate 110.
Metal traces and pads are made of metals with low resistivity to reduce signal delay, such as, but not limited to, aluminum (Al), copper (Cu), silver (Ag), and alloys thereof. isn't it.

An insulating layer 80 is formed over the metal wiring and pads.
Insulating layer 80 is made of inorganic insulating materials such as silicon oxide and/or silicon nitride, or low dielectric constant (low K) materials such as SiC, SiCOH, SiCO, and SiOF.
Insulating layer 80 has trenches 85 that expose charge storage 55 .
Trench 85 is filled with charging material.

The photoelectric conversion element 100 described above is formed on the insulating layer 80.
The photoelectric conversion element 100 includes the first electrode 10, the second electrode 20, the photoelectric conversion layer 30, and the inorganic nanolayer 40, as described above.
The second electrode 20 is a light-receiving electrode, and the first electrode 10 is connected to the charge storage 55 .
Although the photoelectric conversion element 100 shown in FIG. 1 is illustrated in FIG. 3, the photoelectric conversion element 200 shown in FIG. 2 can also be applied in the same manner.
The photoelectric conversion elements (100, 200) have been described above.

A color filter layer 70 is formed on the photoelectric conversion element 100.
The color filter layer 70 includes a blue filter 70a formed on a blue pixel, a red filter 70b formed on a red pixel, and a green filter 70c formed on a green pixel.
However, the present invention is not limited thereto, and may include a cyan filter, a magenta filter, and/or a yellow filter instead of at least one of the blue filter 70a, the red filter 70b, and the green filter 70c, or the blue filter 70a, the red filter 70b and the green filter 70c.
An insulating film (not shown) is additionally formed between the photoelectric conversion element 100 and the color filter layer 70.

A condenser lens (not shown) is further formed on the color filter layer 70.
A condensing lens controls the direction of incident light and focuses the light on one point.
The condenser lens may be, for example, cylindrical or hemispherical, but is not limited thereto.

FIG. 4 is a cross-sectional view showing a schematic configuration of an organic CMOS image sensor according to another embodiment of the present invention.
Referring to FIG. 4, an image sensor 400 according to an embodiment of the present invention includes a semiconductor substrate 110, an insulating layer 80, a photoelectric conversion element 100, and a color filter layer 70, similar to the embodiments described above.
The specific explanation is as described above.

However, the image sensor 400 according to this embodiment is different from the above-described embodiments in that the arrangement of the first electrode 10 and the second electrode 20 is different.
That is, the first electrode 10 is a light receiving electrode, and the second electrode 20 is connected to the charge storage 55.
Although FIG. 4 exemplarily shows a structure in which the photoelectric conversion elements 100 in FIG. 1 are stacked, the structure in which the photoelectric conversion elements 200 in FIG. 2 are stacked can be similarly applied.
The photoelectric conversion elements (100, 200) have been described above.

FIG. 5 is a plan view schematically showing an organic CMOS image sensor according to an embodiment of the present invention, and FIG. 6 is a cross-sectional view schematically showing the structure of the organic CMOS image sensor of FIG.
Referring to FIGS. 5 and 6, an image sensor 500 according to an embodiment of the present invention includes a semiconductor substrate 110 on which a photo-sensing element (50a, 50b), a transfer transistor (not shown), and a charge storage 55 are integrated. , a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and the photoelectric conversion element 100 described above.

The semiconductor substrate 110 is a silicon substrate, on which photo-sensing elements (50a, 50b), transfer transistors (not shown), and charge storage 55 are integrated.
The light sensing elements (50a, 50b) may be photodiodes.
A photo-sensing element (50a, 50b), a transfer transistor, and/or a charge storage 55 may be integrated for each pixel; by way of example, as shown in the figure, the photo-sensing element (50a, 50b) is a blue pixel. and red pixels, respectively, and charge storage 55 may be included in the green pixels.
The photo-sensing elements (50a, 50b) sense light, the sensed information is transmitted by the transfer transistor, and the charge storage 55 is electrically connected to the first electrode 10 of the photoelectric conversion element 100, and the charge storage 55 information is transmitted by the transfer transistor.

Metal wiring (not shown) and pads (not shown) are also formed on the semiconductor substrate 110.
Metal traces and pads are made of metals with low resistivity to reduce signal delay, such as, but not limited to, aluminum (Al), copper (Cu), silver (Ag), and alloys thereof. It's not a thing.
However, the structure is not limited to the above structure, and metal wiring and pads may be disposed under the photo-sensing elements (50a, 50b).

A lower insulating layer 60 is formed on the metal wiring and pads.
The lower insulating layer 60 is made of an inorganic insulating material such as silicon oxide and/or silicon nitride, or a low dielectric constant (low K) material such as SiC, SiCOH, SiCO, and SiOF.
Lower insulating layer 60 has trenches 85 that expose charge storage 55 .
Trench 85 is filled with charging material.

A color filter layer 70 is formed on the lower insulating layer 60 .
The color filter layer 70 includes a blue filter 70a formed in the blue pixel and a red filter 70b formed in the red pixel.
Although this embodiment describes an example without a green filter, it is also possible to include a green filter depending on the case.
Further, a cyan filter, a magenta filter, and/or a yellow filter may be included instead of the blue filter 70a and/or the red filter 70b, or may be further included in addition to the blue filter 70a and the red filter 70b.

An upper insulating layer 80 is formed on the color filter layer 70 .
The upper insulating layer 80 is flattened by eliminating the step caused by the color filter layer 70.
The upper insulating layer 80 and the lower insulating layer 60 have contact holes (not shown) exposing the pads and trenches 85 exposing the charge storage 55 of the green pixel.

The photoelectric conversion element 100 described above is formed on the upper insulating layer 80.
The photoelectric conversion element 100 includes the first electrode 10, the second electrode 20, the photoelectric conversion layer 30, and the inorganic nanolayer 40, as described above.
The second electrode 20 is a light receiving electrode, and the first electrode 10 is connected to the charge storage 55 .

Although FIG. 6 exemplarily shows a structure in which the photoelectric conversion elements 100 in FIG. 1 are stacked, the structure in which the photoelectric conversion elements 200 in FIG. 2 are stacked can be similarly applied.
The photoelectric conversion elements (100, 200) have been described above.
A condenser lens (not shown) is further formed on the photoelectric conversion element 100.
A condenser lens controls the direction of incident light and focuses the light at one point.
The condenser lens may be, for example, cylindrical or hemispherical, but is not limited thereto.

FIG. 7 is a cross-sectional view showing a schematic configuration of another example of the organic CMOS image sensor shown in FIG.
Referring to FIG. 7, the image sensor 600 according to the present embodiment includes a semiconductor substrate 110 on which photo-sensing elements (50a, 50b), a transfer transistor (not shown), and a charge storage 55 are integrated, as in the previous embodiments. It includes a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a photoelectric conversion element 100.

However, the image sensor 600 according to this embodiment is different from the above-described embodiments in that the positions of the first electrode 10 and the second electrode 20 are different.
That is, the first electrode 10 is a light receiving electrode, and the second electrode 20 is connected to the charge storage 55.
Although FIG. 7 exemplarily shows a structure in which the photoelectric conversion elements 100 in FIG. 1 are stacked, the structure in which the photoelectric conversion elements 200 in FIG. 2 are stacked can be similarly applied.

FIG. 8 is a sectional view showing a schematic configuration of still another example of the organic CMOS image sensor shown in FIG.
The image sensor 700 according to the present embodiment includes a semiconductor substrate 110 in which photo-sensing elements (50a, 50b), a transfer transistor (not shown), and a charge storage 55 are integrated, and an upper portion having a trench 85, similar to the above-described embodiments. It includes an insulating layer 80 and a photoelectric conversion element 100.

However, the image sensor 700 according to the present embodiment differs from the above-described embodiments in that the photo-sensing elements (50a, 50b) are stacked vertically, and the color filter layer 70 is omitted.
The photo-sensing elements (50a, 50b) are electrically connected to a charge storage (not shown) and transferred by a transfer transistor.
The photo-sensing elements (50a, 50b) can selectively absorb light in each wavelength range depending on the lamination depth.
Although FIG. 8 exemplarily shows a structure in which the photoelectric conversion elements 100 in FIG. 1 are stacked, the structure in which the photoelectric conversion elements 200 in FIG. 2 are stacked can be similarly applied.

FIG. 9 is a sectional view showing a schematic configuration of still another example of the organic CMOS image sensor shown in FIG.
Referring to FIG. 9, an image sensor 800 according to the present embodiment includes a semiconductor substrate 110 on which photo-sensing elements (50a, 50b), transfer transistors (not shown), and charge storage 55 are integrated, similar to the above-described embodiments. , an upper insulating layer 80 having a trench 85, and a photoelectric conversion element 100.

However, the image sensor 800 according to this embodiment is different from the above-described embodiments in that the positions of the first electrode 10 and the second electrode 20 are different.
That is, the first electrode 10 is a light receiving electrode, and the second electrode 20 is connected to the charge storage 55.
Although FIG. 9 exemplarily shows a structure in which the photoelectric conversion elements 100 in FIG. 1 are stacked, a structure in which the photoelectric conversion elements 200 in FIG. 2 are stacked can be similarly applied.

FIG. 10 is a plan view schematically showing an organic CMOS image sensor according to still another embodiment, and FIG. 11 is a cross-sectional view showing an example of a schematic configuration of the organic CMOS image sensor of FIG. 10.
The organic CMOS image sensor 900 according to this embodiment includes a green photoelectric conversion element that selectively absorbs light in the green wavelength range, a blue photoelectric conversion element that selectively absorbs light in the blue wavelength range, and a blue photoelectric conversion element that selectively absorbs light in the red wavelength range. It has a structure in which selectively absorbing red photoelectric conversion elements are stacked.

The organic CMOS image sensor 900 according to this embodiment includes a semiconductor substrate 110, a lower insulating layer 60, an intermediate insulating layer 65, an upper insulating layer 80, a first photoelectric conversion element 100a, a second photoelectric conversion element 100b, and a third photoelectric conversion element. Contains 100c.
The semiconductor substrate 110 may be a silicon substrate, in which transfer transistors (not shown) and charge storage (55a, 55b, 55c) are integrated.
A metal wiring (not shown) and a pad (not shown) are formed on the semiconductor substrate 110, and a lower insulating layer 60 is formed on the metal wiring and the pad.
A first photoelectric conversion element 100a is formed on the lower insulating layer 60.

The first photoelectric conversion element 100a includes a first electrode 10a and a second electrode 20a facing each other, a photoelectric conversion layer 30a and an inorganic nano layer 40a arranged between the first electrode 10a and the second electrode 20a.
The first electrode 10a, the second electrode 20a, the photoelectric conversion layer 30a, and the inorganic nanolayer 40a are as described above, and the photoelectric conversion layer 30a has a wavelength range of one of red, blue, and green. It can selectively absorb light.
For example, the first photoelectric conversion element 100a is a red photoelectric conversion element.
The second electrode 20a is a light receiving electrode, and the first electrode 10a is connected to a charge storage 55a.

An intermediate insulating layer 65 is formed on the first photoelectric conversion element 100a.
A second photoelectric conversion element 100b is formed on the intermediate insulating layer 65.
The second photoelectric conversion element 100b includes a first electrode 10b and a second electrode 20b facing each other, a photoelectric conversion layer 30b disposed between the first electrode 10b and the second electrode 20b, and an inorganic nanolayer 40b.
The first electrode 10b, the second electrode 20b, the photoelectric conversion layer 30b, and the inorganic nanolayer 40b are as described above. can be selectively absorbed.
For example, the second photoelectric conversion element 100b is a blue photoelectric conversion element.
The second electrode 20b is a light receiving electrode, and the first electrode 10b is connected to the charge storage 55b.

An upper insulating layer 80 is formed on the second photoelectric conversion element 100b.
The lower insulating layer 60, the middle insulating layer 65, and the upper insulating layer 80 have a plurality of through holes exposing charge storage (55a, 55b, 55c).

A third photoelectric conversion element 100c is formed on the upper insulating layer 80.
The third photoelectric conversion element 100c includes a first electrode 10c and a second electrode 20c facing each other, a photoelectric conversion layer 30c disposed between the first electrode 10c and the second electrode 20c, and an inorganic nanolayer 40c.
The first electrode 10c, the second electrode 20c, the photoelectric conversion layer 30c, and the inorganic nanolayer 40c are as described above. can be selectively absorbed.
For example, the third photoelectric conversion element 100c is a green photoelectric conversion element, and the above-described photoelectric conversion element 100 can be applied thereto.
The second electrode 20c is a light receiving electrode, and the first electrode 10c is connected to a charge storage 55c.

A condenser lens (not shown) may further be formed on the photoelectric conversion element 100c.
A condensing lens controls the direction of incident light and focuses the light on one point.
The condenser lens may be, for example, cylindrical or hemispherical, but is not limited thereto.

In the figure, the photoelectric conversion element 100 of FIG. 1 is illustrated as a first photoelectric conversion element 100a, a second photoelectric conversion element 100b, and a third photoelectric conversion element 100c, but the photoelectric conversion element 200 shown in FIG. Can be applied.
Although the figure shows a structure in which the first photoelectric conversion element 100a, the second photoelectric conversion element 100b, and the third photoelectric conversion element 100c are sequentially stacked, the stacking order is not limited to this and can be changed in various ways. .
As described above, by having the structure in which the first photoelectric conversion element 100a, the second photoelectric conversion element 100b, and the third photoelectric conversion element 100c that absorb light in different wavelength regions are stacked, the size of the image sensor can be reduced. It is possible to further reduce this and realize a miniaturized image sensor.

FIG. 12 is a sectional view showing another example of the schematic configuration of the organic CMOS image sensor shown in FIG. 10.
Referring to FIG. 12, the organic CMOS image sensor 1000 according to the present embodiment includes a semiconductor substrate 110, a lower insulating layer 60, an intermediate insulating layer 65, an upper insulating layer 80, a first photoelectric conversion element 100a, It includes a second photoelectric conversion element 100b and a third photoelectric conversion element 100c.
However, unlike the embodiment described above, the positions of the first electrode 10 and the second electrode 20 of the first photoelectric conversion element 100a, the second photoelectric conversion element 100b, and the third photoelectric conversion element 100c are changed.
That is, the first electrodes (10a, 10b, 10c) are light receiving electrodes, and the second electrodes (20a, 20b, 20c) are connected to charge storage (55a, 55b, 55c).

FIG. 13 is a plan view schematically showing an organic CMOS image sensor according to still another embodiment of the present invention, and FIG. 14 is a cross-sectional view showing an example of a schematic configuration of the organic CMOS image sensor of FIG. 13.
Referring to FIGS. 13 and 14, an organic CMOS image sensor 1100 includes a photoelectric conversion element 90 disposed on a semiconductor substrate 110, and the photoelectric conversion element 90 includes a plurality of photoelectric conversion elements (90-1, 90-2, 90-3).

The plurality of photoelectric conversion elements (90-1, 90-2, 90-3) can convert light in different wavelength ranges (for example, blue light, green light, or red light) into electrical signals.
Referring to FIG. 14, a plurality of photoelectric conversion elements (90-1, 90-2, 90-3) are arranged horizontally on the semiconductor substrate 110 and lined up on the surface 110a of the semiconductor substrate 110. They partially or completely overlap each other in the extended direction.
Each photoelectric conversion element (90-1, 90-2, 90-3) is connected to charge storage 55 integrated within semiconductor substrate 110 via trench 85.
Each photoelectric conversion element (90-1, 90-2, 90-3) may be one of the photoelectric conversion elements (100, 200) described above.

As an example, two or more photoelectric conversion elements (90-1, 90-2, 90-3) have a common comprising different portions of successive layers of.
As an example, a plurality of photoelectric conversion elements (90-1, 90-2, 90-3) share a common first electrode 10 and/or a common second electrode 20.
As an example, two or more photoelectric conversion elements (90-2, 90-2, 90-3) have different photoelectric conversion layers 30 that can absorb incident light in different wavelength regions.
As an example, two or more photoelectric conversion elements (90-1, 90-2, 90-3) include inorganic nanolayers 40 with different configurations.
Other structures of the organic CMOS image sensor 1100 may be the same as one or more of the organic CMOS images described in FIGS. 3-12.

FIG. 15 is a sectional view showing another example of the schematic configuration of the organic CMOS image sensor according to the embodiment of the present invention.
Referring to FIG. 15, an organic CMOS image sensor 1200 includes a semiconductor substrate 110 and photoelectric conversion elements (90-1, 91) stacked on the semiconductor substrate 110.
The photoelectric conversion element 91 includes a plurality of photoelectric conversion elements (90-2, 90-3), and the plurality of photoelectric conversion elements (90-2, 90-3) are arranged on the surface 110a of the semiconductor substrate 110. They are arranged so that they overlap in the direction of extension.

The plurality of photoelectric conversion elements (90-1, 90-2, 90-3) can photoelectrically convert light in different wavelength ranges (for example, blue light, green light, or red light) into electrical signals.
As an example, the photoelectric conversion element (91) includes a plurality of horizontally arranged photoelectric conversion elements (90-2, 90-3) that can absorb light in different wavelength regions.
As an example, the photoelectric conversion element 91 photoelectrically converts light in one wavelength range selected from blue light, green light, and red light.
As an example, the photoelectric conversion element 91 completely or partially overlaps with the photoelectric conversion element (90-1).
Other structures of organic CMOS image sensor 1200 may be the same as one or more of the organic CMOS images described in FIGS. 3-12.

FIG. 16 is a cross-sectional view showing still another example of the schematic configuration of the organic CMOS image sensor according to the embodiment of the present invention.
Referring to FIG. 16, an organic CMOS image sensor 1300 includes a semiconductor substrate 110 on which a photo-sensing element (50a, 50b), a transfer transistor (not shown), and a charge storage 55 are integrated, and is arranged on the semiconductor substrate 110. The semiconductor substrate 110 includes an upper insulating layer 80 and a color filter layer 70 , a lower insulating layer 60 located under a semiconductor substrate 110 , and a photoelectric conversion element 90 .
The photoelectric conversion element 90 may be the photoelectric conversion element (100, 200) described above.

In FIG. 16, the photoelectric conversion element 90 is located under the semiconductor substrate 110, so that the photoelectric conversion element 90 and the color filter layer 70 are arranged separately from the photosensitive elements (50a, 50b).
Other structures of the organic CMOS image sensor 1300 may be the same as one or more of the organic CMOS images described in FIGS. 3-12.
The organic sensors including the photoelectric conversion elements and image sensors described above can be applied to various electronic devices, such as mobile phones, digital cameras, etc., but are not limited thereto.

FIG. 17 is a diagram showing a schematic configuration of an electronic device according to an embodiment of the present invention.
Referring to FIG. 17, an electronic device 1700 includes a processor 1720, a memory 1730, and an organic CMOS image sensor 1740 electrically connected via a bus 1710.
Organic CMOS image sensor 1740 may be one according to the embodiments described above.
Memory 1730, which is a non-transitory computer readable medium, stores the instruction program.
Processor 1720 executes stored instruction programs to perform one or more functions.
In one example, processor 1720 processes electrical signals generated by organic CMOS image sensor 1740.
Processor 1720 generates output (eg, an image displayed on a display interface) based on such processing.

Hereinafter, the above-described embodiments will be explained in more detail with reference to Examples shown below.
However, the following examples are merely for illustrative purposes and are not intended to limit the scope of rights.

<Example 1>
ITO is laminated on a glass substrate by sputtering to form a 150 nm thick anode.
Next, a compound represented by the following chemical formula A is deposited on the anode to form a charge assisting layer having a thickness of 5 nm.
Next, on the charge auxiliary layer, a p-type semiconductor (λ _max : 545 nm) represented by the chemical formula B-1 shown below and an n-type semiconductor which is fullerene (C60) are co-evaporated at a volume ratio of 1:1 to form a 100 nm layer. Form a thick photoelectric conversion layer.
Next, Yb (WF: 2.6 eV) is thermally evaporated onto the photoelectric conversion layer to form an inorganic nanolayer with a thickness of 1.5 nm.
Then, ITO (WF: 4.7 eV) is sputtered onto the inorganic nanolayer to form a 7 nm thick cathode.
Next, aluminum oxide (Al ₂ O ₃ ) is deposited on the cathode to form a 50 nm thick anti-reflection layer and sealed with a glass plate to fabricate a photoelectric conversion element.

<Comparative example 1>
A photoelectric conversion element is manufactured by the same method as in Example 1 except that an inorganic nanolayer is not formed.

<Example 2>
A photoelectric conversion element was manufactured in the same manner as in Example 1, except that a 90 nm thick photoelectric conversion layer was formed by co-evaporating a p-type semiconductor and an n-type semiconductor at a volume ratio of 1.2:1. .

<Comparative example 2>
A photoelectric conversion element is manufactured by the same method as in Example 2 except that an inorganic nanolayer is not formed.

<Example 3>
A photoelectric conversion element was manufactured by the same method as in Example 1, except that a photoelectric conversion layer with a thickness of 80 nm was formed by co-evaporating a p-type semiconductor and an n-type semiconductor at a volume ratio of 2.5:1. .

<Comparative example 3>
A photoelectric conversion element is manufactured by the same method as in Example 3 except that an inorganic nanolayer is not formed.

≪Evaluation I≫
Characteristics of remaining electrons of photoelectric conversion devices according to Examples and Comparative Examples will be evaluated.
The characteristics of residual electrons refer to the amount of charge that is photoelectrically converted in one frame and remains unused for signal processing, and the charge of the previous frame is read in the next frame, and is compared with the example. The photoelectric conversion element according to the example is irradiated with light in a wavelength range in which photoelectric conversion can occur for a certain period of time, and after the light is turned off, evaluation is made from the amount of current measured in units of 10 ⁻⁶ seconds using a “Keithley 2400” device.

表１～３を参照すると、無機ナノ層を含む実施例による光電変換素子は、無機ナノ層を含まなかった比較例による光電変換素子と比較して残留電子の特性が改善されたことを確認することができる。 The results are shown in Tables 1 to 3.

Referring to Tables 1 to 3, it is confirmed that the photoelectric conversion device according to the example including the inorganic nanolayer has improved characteristics of residual electrons compared to the photoelectric conversion device according to the comparative example that does not include the inorganic nanolayer. be able to.

≪Evaluation II≫
The photoelectric conversion efficiency of the photoelectric conversion elements according to Examples and Comparative Examples will be evaluated.
Photoelectric conversion efficiency (EQE) is evaluated by the "Incident Photon to Current Efficiency" (IPCE) method in the wavelength range of 400 nm to 720 nm.

表４、５を参照すると、実施例による光電変換素子は比較例による光電変換素子と比較して等しいか改善された光電変換効率を示すことを確認することができる。 The results are shown in Tables 4 and 5.

Referring to Tables 4 and 5, it can be confirmed that the photoelectric conversion device according to the example has the same or improved photoelectric conversion efficiency as compared to the photoelectric conversion device according to the comparative example.

≪Evaluation III≫
An organic CMOS image sensor to which the photoelectric conversion elements according to Examples and Comparative Examples are applied is designed, and the YSNR10 of the organic CMOS image sensor is evaluated.
YSNR10 of an organic CMOS image sensor is the illuminance (unit: lux) at which the signal/noise ratio is 10, where the signal is an RGB source signal calculated by the FDTD (finite difference time domain method) method. (RGB raw signal) is the sensitivity of a signal obtained through a color correction stage using a color correction matrix (CCM), and noise is noise generated when measuring a signal with an organic CMOS image sensor.
The color correction step is a process of performing image processing on the RGB source signals obtained from the organic CMOS image sensor to reduce the difference from the actual color.
The smaller the YSNR10 value, the better the image characteristics at low illuminance.

表６を参照すると、実施例による光電変換素子は比較例による光電変換素子と比較してＹＳＮＲ１０が低くなることを確認することができ、これから有機ＣＭＯＳイメージセンサの感度が改善される可能性があることを予想することができる。 The results are shown in Table 6.

Referring to Table 6, it can be confirmed that the photoelectric conversion element according to the example has a lower YSNR10 than the photoelectric conversion element according to the comparative example, and there is a possibility that the sensitivity of the organic CMOS image sensor will be improved in the future. can be predicted.

Note that the present invention is not limited to the above-described embodiments. Various modifications can be made without departing from the technical scope of the present invention.

10, 10a, 10b, 10c First electrode 20, 20a, 20b, 20c Second electrode 30, 30a, 30b, 30c Photoelectric conversion layer 40, 40a, 40b, 40c Inorganic nano layer 45 Charge auxiliary layer 50a, 50b, 50c Light Sensing element 55, 55a, 55b, 55c Charge storage 60 Lower insulating layer 65 Intermediate insulating layer 70 Color filter layer 70a, 70b, 70c (Blue, Red, Green) filter 80 (Top) Insulating layer 85 Trench 90, 91, 100, 200 Photoelectric conversion elements 100a, 100b, 100c (first to third) photoelectric conversion elements 110 Semiconductor substrate 300, 400, 500, 600, 700, 800 Image sensor 900, 1000, 1100, 1200, 1300, 1740 Organic CMOS image sensor 1700 Electronic equipment 1710 Bus
1720 Processor 1730 Memory

Claims (19)

A first electrode and a second electrode facing each other,
a photoelectric conversion layer disposed between the first electrode and the second electrode, which absorbs light in at least a part of the wavelength range and converts it into an electrical signal;
an inorganic nanolayer disposed between the first electrode and the photoelectric conversion layer and containing a lanthanum group element ;
A photoelectric conversion element , wherein the lanthanum group element includes ytterbium (Yb) . The photoelectric conversion element according to claim 1, wherein the inorganic nanolayer is in contact with the first electrode. One surface of the inorganic nanolayer is in contact with the first electrode,
The photoelectric conversion element according to claim 1, wherein the other surface of the inorganic nanolayer is in contact with the photoelectric conversion layer. The photoelectric conversion element according to claim 1, wherein the first electrode is a transparent electrode with a light transmittance of 80% or more, or a reflective electrode with a light transmittance of less than 10%. 5. The photoelectric conversion element according to claim 4 , wherein the transparent electrode includes at least one of an oxide conductor and a carbon conductor. The photoelectric conversion element according to claim 1, wherein the inorganic nanolayer has a thickness of 5 nm or less. The photoelectric conversion element according to claim 1, wherein the inorganic nanolayer has a thickness of 2 nm or less. The photoelectric conversion element according to claim 1, wherein the first electrode is a cathode and the second electrode is an anode. a first electrode containing a transparent conductor with a light transmittance of 80% or more or a reflective conductor with a light transmittance of less than 10%;
a photoelectric conversion layer disposed on the first electrode and absorbing light in at least a part of the wavelength range and converting it into an electrical signal;
a second electrode disposed on the photoelectric conversion layer,
The surface of the first electrode facing the photoelectric conversion layer is covered with an inorganic nanolayer with a thickness of 5 nm or less,
The effective work function at the surface of the first electrode facing the photoelectric conversion layer is smaller than the work function of the transparent conductor or the reflective conductor,
The inorganic nanolayer includes an inorganic substance,
A photoelectric conversion element , wherein the inorganic substance includes a lanthanum group element, and the lanthanum group element includes ytterbium (Yb) . Claim 9, wherein the difference between the work function of the transparent conductor or the reflective conductor and the effective work function at the surface of the first electrode facing the photoelectric conversion layer is 0.5 eV or more. The photoelectric conversion element described. The work function of the transparent conductor or the reflective conductor is 4.5 eV or more,
10. The photoelectric conversion element according to claim 9 , wherein an effective work function on the surface of the first electrode facing the photoelectric conversion layer is 4.0 eV or less. 12. The photoelectric conversion element according to claim 11 , wherein an effective work function on the surface of the first electrode facing the photoelectric conversion layer is 3.0 eV or less. The photoelectric conversion element according to claim 9 , wherein the transparent conductor includes an oxide conductor or a carbon conductor. The photoelectric conversion element according to claim 9 , wherein the inorganic nanolayer has a thickness of 2 nm or less. 10. The photoelectric conversion element according to claim 9, wherein the first electrode is a cathode and the second electrode is an anode. An electronic device comprising the photoelectric conversion element according to claim 1 . An organic sensor comprising the photoelectric conversion element according to any one of claims 1 to 15 . The organic sensor according to claim 17 , wherein the organic sensor is an organic CMOS image sensor. An electronic device comprising the organic sensor according to claim 17 .

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