JP2009060051A - Organic solar cell and optical sensor - Google Patents

Abstract

A solar cell using a semiconductor that transmits visible light and absorbs power by infrared light is provided.
A photoelectric conversion layer 1 containing an organic semiconductor having a light absorption peak in an infrared light region is provided between two electrodes 2 and 2. According to this organic solar cell A, infrared light occupying most of the solar energy can be used for solar cell power generation, and a highly efficient solar cell can be obtained. In addition, since an organic semiconductor having a light absorption peak in the infrared region has a high visible light transmittance, the photoelectric conversion layer 1 can be formed transparently. Further, when combined with a solar cell that generates power by absorbing the visible light region or a solar cell that generates power by absorbing the ultraviolet light region, the power generation efficiency can be further improved.
[Selection] Figure 1

Description

  The present invention relates to an organic solar cell and an optical sensor configured using the organic solar cell.

  A solar cell generally has a structure in which a semiconductor is sandwiched between a transparent electrode and a metal electrode, and when light enters the semiconductor through the transparent electrode, it generates power by generating carriers by a photoelectric conversion effect. Yes. Incident light is classified into ultraviolet light (wavelength 400 nm or less), visible light (400 to 700 nm), and infrared light (700 nm or more). The wavelength of incident light suitable for power generation varies depending on the type of semiconductor.

  Examples of semiconductors generally employed in such solar cells include crystalline silicon, amorphous silicon, inorganic compound semiconductors, and organic semiconductors. Crystalline silicon and inorganic compound semiconductors absorb from the visible light to the infrared light region, and amorphous silicon absorbs in the visible light region, so that it is a semiconductor having colors such as black, blue, and brown. On the other hand, since organic semiconductors have absorption in a specific wavelength region from visible light to infrared light, the color of the semiconductor varies greatly depending on the type of dye.

Moreover, as a transparent solar cell, there is one using a metal oxide as a semiconductor (see Patent Document 1). This transparent solar cell absorbs ultraviolet light and generates electricity. This solar cell utilizes the fact that the absorption of an inorganic material is defined by a band gap, and a high band gap semiconductor such as a metal oxide can only absorb a short wavelength region (ultraviolet region). Here, there is an inorganic material having a low band gap capable of absorbing infrared light. In this case, however, all light such as infrared light, visible light, and ultraviolet light is absorbed.
JP 2003-324206 A

  As described above, as a conventional solar cell that can transmit visible light, there is a solar cell that generates power by absorbing ultraviolet light as in Patent Document 1, but in this case, since the absorption band is narrow, a highly efficient solar cell is used. It is difficult to obtain a battery.

  On the other hand, if a solar cell that transmits visible light and absorbs infrared light to generate power can be obtained, since infrared light occupies most of the solar energy, a transparent and highly efficient solar cell can be obtained. It is thought that it can be obtained. If such a solar cell is applied to, for example, a window of a house building material or a car window, an application as a transparent window having both a heat insulating function and a power generation function can be expected.

  In addition, when combined with a semiconductor that generates power by absorbing visible light, it can generate power by absorbing light in a wide band from visible light to infrared light, further improving the efficiency of solar cells. I can also expect that.

  Moreover, if such a solar cell is used, it can be applied to an optical sensor that detects infrared light.

  However, solar cells using a semiconductor that transmits visible light and absorbs power with infrared light have not yet been developed.

  The present invention has been made in view of the above points, and an object thereof is to provide a solar cell using a semiconductor that transmits visible light and absorbs power by infrared light and an optical sensor using the solar cell. To do.

  As a result of intensive studies, the present inventors have focused on the fact that the organic semiconductor is different from the inorganic material in that the absorption region is defined by the position of the HOMO-LUMO in the intramolecular energy level and its gap, and the light is transmitted in the infrared region. The present inventors have found that an organic semiconductor having an absorption peak of 2 can be used for a solar cell, and completed the present invention.

  That is, the organic solar cell A according to claim 1 is provided with a photoelectric conversion layer 1 containing an organic semiconductor having an absorption peak of light in an infrared region between two electrodes 2 and 2. Features.

  According to a second aspect of the present invention, in the first aspect, the two electrodes 2 and 2 are both transparent electrodes 2, and the photoelectric conversion layer 1 disposed between the two electrodes 2 and 2 is red. Only the photoelectric conversion layer 1 containing an organic semiconductor having an absorption peak of light in an external light region is characterized.

  The invention according to claim 3 is the photoelectric conversion layer 1 including an organic semiconductor having an absorption peak of light in the infrared light region between the two electrodes 2 and 2, and the visible light region or A plurality of photoelectric conversion layers 1 including a photoelectric conversion layer 1 having a light absorption peak in an ultraviolet light region are provided with being laminated via a light-transmitting intermediate electrode 3.

  The invention according to claim 4 is the n-type according to any one of claims 1 to 3, wherein the photoelectric conversion layer 1 containing an organic semiconductor having an absorption peak of light in the infrared region has light transmittance. A semiconductor is contained, and the organic semiconductor and the n-type semiconductor are in contact with each other in the photoelectric conversion layer 1.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the organic semiconductor having a light absorption peak in the infrared light region is naphthalocyanine or a naphthalocyanine derivative.

  The optical sensor which concerns on Claim 6 is a photoelectric conversion part comprised from the organic solar cell A as described in any one of Claims 1 thru | or 5, The detection part which detects the change of the electrical property of this photoelectric conversion part, It is characterized by providing.

  According to the organic solar cell A according to the first aspect, infrared light occupying most of the solar energy can be used for solar cell power generation, and a highly efficient solar cell can be obtained. In addition, since an organic semiconductor having a light absorption peak in the infrared region has a high visible light transmittance, the photoelectric conversion layer 1 can be formed transparently. Further, when combined with a solar cell that generates power by absorbing the visible light region or a solar cell that generates power by absorbing the ultraviolet light region, the power generation efficiency can be further improved.

  According to the invention which concerns on Claim 2, the organic solar cell A can be formed transparently by comprising the organic solar cell A with the transparent photoelectric converting layer 1 and the transparent electrode 2, for example, a housing building material A transparent window having both a heat insulating function and a power generation function can be formed by applying to a window or a car window.

  According to the third aspect of the invention, in particular, the photoelectric conversion layer 1 containing an organic semiconductor having an absorption peak of light in the infrared light region generates power by converting infrared light into electric energy and visible light. The other photoelectric conversion layer 1 containing a semiconductor having a light absorption peak in the region or the ultraviolet light region can generate electric power by converting visible light or ultraviolet light into electric energy, and absorbs the infrared light region. Thus, the solar cell that generates power and the solar cell that generates power by absorbing the visible light region or the ultraviolet light region can be integrated, and more efficient power generation using light over a wide range can be performed.

  According to the invention which concerns on Claim 4, the electric power generation efficiency of the organic solar cell A can further be improved.

  According to the invention of claim 5, by using naphthalocyanine and a naphthalocyanine derivative having high infrared light absorbance and low visible light absorbance as organic semiconductors, it is possible to obtain a more efficient organic solar cell A. it can.

  According to the optical sensor of the sixth aspect of the invention, it can be suitably used particularly for detecting light including infrared light, and is used as a light receiving device for optical communication using infrared light or an infrared light transparent light sensor. It is something that can be done.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 shows an example of an organic solar cell A. This organic solar cell A is configured by sandwiching a photoelectric conversion layer 1 containing an organic semiconductor having a light absorption peak in an infrared region between two electrodes 2 and 2.

  The two electrodes 2 and 2 function as one having a positive electrode and the other as a negative electrode. The two electrodes 2 and 2 form an electrode having conductivity and translucency, and have good solar cell characteristics. The sheet resistance is preferably 20Ω / □ or less.

  By using at least one of the electrodes 2 as the transparent electrode 2 having light transmittance, light incident on the organic solar cell A through the transparent electrode 2 can be used for power generation. The two electrodes 2 and 2 may be both transparent electrodes 2, and in this case, the entire organic solar cell A can be formed transparently.

  Of these two electrodes 2 and 2, the electrode 2 functioning as a positive electrode preferably has a large work function in order to efficiently collect holes, and the work function is particularly preferably 4.9 to 5.1 eV. The thing of the range of is preferable. Specific examples of the material for the electrode 2 include conductive transparent materials such as ITO (indium tin oxide), AZO, and GZO.

  The electrode 2 functioning as a negative electrode preferably has a small work function in order to efficiently collect electrons, and particularly preferably has a work function in the range of 3 to 4.5 eV. Specific examples of such a material for the second electrode 2 include Al, Ca, Mg, Ag, Cu, Pt, and alloys thereof.

  The thickness of these electrodes 2 is not particularly limited, but is preferably in the range of 50 to 200 nm in order to ensure good conductivity and light transmittance.

  The photoelectric conversion layer 1 contains an organic semiconductor having a light absorption peak in the infrared region, and is preferably configured as a layer including the organic semiconductor and a light-transmitting n-type semiconductor.

  An organic semiconductor having a light absorption peak in the infrared light region has an absorption peak in the infrared light region, and the integrated absorbance value in the infrared light region is larger than the integrated absorbance value in the visible light region. It is preferable that there is no absorption peak in the light region. There may be a large absorption peak in the ultraviolet region.

  As such an organic semiconductor, a π-conjugated polymer or the like is preferable, and those having polyparaphenylene vinylene, polythiophene, polyfluorene, polyaniline, etc. as the main skeleton are preferable in terms of hole conductivity. What has increased absorption in a long wavelength region by having a system can be used.

Examples of such organic semiconductors include naphthalocyanine or naphthalocyanine derivatives as shown in the following formulas (1) to (3). M in each formula is a central metal, and can include various metals such as Cu, Zn, Ti, Ni, and Fe. In addition, examples of the substituent A in the formulas (2) and (3) include —R, —OR, a halogen group, and the like, and examples of the R include a butyl group (—CH ₂ CH ₂ CH ₂ CH ₃ ) And a tertiary butyl group (—C (CH ₃ ) ₃ ), or organic groups containing C, H, N, S, halogen and the like.

Here, phthalocyanine (M is a central metal, and various metals such as Cu, Zn, Ti, Ni, and Fe) represented by the following formula (4) have absorption in the visible light region, and conventionally, organic solar cell A When the π-conjugated system is extended from this phthalocyanine, the maximum absorption peak shifts to the longer wavelength side, increasing the absorbance in the infrared region and increasing the absorbance in the visible region. For example, in the case of naphthalocyanine represented by the formula (1), the maximum absorption peak is shifted to close to 700 nm, and the substituent R in the formula (2) is a butyl group (C ₄ H ₉ ). In this case, the absorption peak is increased to 870 nm.

  Of course, it is possible to synthesize an organic semiconductor having an absorption peak in the infrared light region by an organic material other than phthalocyanine due to a molecular structure and a substituent effect.

  Further, the light-transmitting n-type semiconductor functions as an electron-accepting material, and for example, fullerene, a fullerene derivative, or the like can be used.

  The photoelectric conversion layer 1 is preferably formed by combining an organic semiconductor and an n-type semiconductor so that the organic semiconductor and the n-type semiconductor are in contact within the photoelectric conversion layer 1. For example, a pn stacked structure in which a layer containing an organic semiconductor (p layer) and an n-type semiconductor (n layer) are stacked, a bulk heterostructure in which an organic semiconductor and an n-type semiconductor are mixed, a p layer and an n layer A mixed layer in which an organic semiconductor and an n-type semiconductor are mixed by co-evaporation or a composite layer in which a plurality of thin films made of an organic semiconductor and a thin film made of an n-type semiconductor are alternately stacked. The organic solar cell A can be improved in performance by forming it in a pin structure or the like.

  Although the thickness of the photoelectric converting layer 1 is set suitably, it can be set as the range of 50-100 nm, for example.

  In addition, by interposing an appropriate buffer layer such as a hole transport layer or an electron transport layer between the photoelectric conversion layer 1 and the electrode 2, the carrier can be selectively transported or carrier recombination can be reduced. Further efficiency improvement can be achieved.

  Such an organic solar cell A can be formed by sequentially laminating the above layers on a substrate. As the substrate, a transparent substrate having insulating properties can be used. The substrate may be colorless and transparent, or may be slightly colored or ground glass. Specific materials for the substrate include soda lime glass, alkali-free glass, various transparent plastics (PE, PP, PS, AS, ABS, PMMA, PVC, PA, POM, PBT, PC, PES, etc.). it can. In laminating each of the above layers, an appropriate method can be adopted. For example, the layers can be sequentially formed into a thin film by a method such as a vacuum deposition method, a sputtering method, an ion plating method, a spin coating method, or a printing method.

  In the organic solar cell A thus formed, when light enters and reaches the photoelectric conversion layer 1, it can generate power by absorbing infrared light, and the infrared light that occupies most of the solar energy is generated. It can be used for solar cell power generation, and power generation efficiency is increased.

  In addition, since an organic semiconductor having a light absorption peak in the infrared light region has a high visible light transmittance, the photoelectric conversion layer 1 can be formed transparently. In particular, the two electrodes 2 and 2 are both transparent. When it is the electrode 2, the whole solar cell can be formed transparently. In this case, the organic solar cell A can be applied to, for example, a window of a house building material or a window of a car to form a transparent window having both a heat insulating function and a power generation function.

  FIG. 2 shows another example of the organic solar battery A. This organic solar cell A includes a photoelectric conversion layer 1 (first photoelectric conversion layer 1a) containing an organic semiconductor having a light absorption peak in the infrared light region as described above between two electrodes 2 and 2. In addition, the photoelectric conversion layer 1 (second photoelectric conversion layer 1b) having a light absorption peak in the visible light region is sandwiched. In the example shown in the figure, the first photoelectric conversion layer 1 a and the second photoelectric conversion layer 1 b are formed by being stacked via the intermediate electrode 4.

  As the two electrodes 2 and 2, the same electrodes as those shown in FIG. 1 can be formed. By using at least one of the electrodes 2 as the transparent electrode 2 having light transmittance, light incident on the organic solar cell A through the transparent electrode 2 can be used for power generation. The two electrodes 2 and 2 may be both transparent electrodes 2.

  Moreover, as the 1st photoelectric converting layer 1a, the thing similar to the photoelectric converting layer 1 in the case shown in FIG. 1 can be formed.

  The second photoelectric conversion layer 1b can be formed as a semiconductor containing a light absorption peak in the visible light region, and preferably includes a layer containing the semiconductor and a light-transmitting n-type semiconductor. Composed.

  A semiconductor having an absorption peak of light in the visible light region has an absorption peak in the visible light region, and an integrated value of absorbance in the visible light region is larger than an integrated value of absorbance in the infrared region. There may be a large absorbance absorption peak in the ultraviolet region.

  As this semiconductor, a π-conjugated polymer or the like is preferable, and those having a main skeleton of polyparaphenylene vinylene, polythiophene, polyfluorene, polyaniline or the like are preferable in terms of hole conductivity. Examples of such semiconductors include phthalocyanine pigments, indigo, thioindigo pigments, quinacridone pigments, merocyanine compounds, cyanine compounds, squalium compounds, charge transfer agents used in organic electrophotographic photoreceptors, and electrically conductive organic charges. A transfer complex etc. can be mentioned, Furthermore, a conductive polymer can be mentioned. As an example, phthalocyanine represented by the above formula (4) can be given.

  Further, as the n-type semiconductor having optical transparency, the same ones as described above can be used.

  The second photoelectric conversion layer 1b is also formed by combining an organic semiconductor and an n-type semiconductor into, for example, a pn stacked structure, a bulk hetero structure, a pin structure, or the like. Performance improvement is possible.

  The intermediate electrode 4 functions as a carrier recombination layer that couples electrons and holes respectively supplied from the photoelectric conversion layers 1 and 1 on both sides to make the two photoelectric conversion layers 1 and 1 conductive. It is preferable to form a material that has conductivity and transmits light. Specific examples of the material for the intermediate electrode 4 include Ag, Al, Ca, Mg, Cu, Pt, and Au, alloys thereof, and metal oxides such as ITO. In order to ensure good light transmittance, it is preferable to form the film thickness of the intermediate electrode 4 in the range of 0.5 to 5 nm.

  As in the case of the organic solar cell A shown in FIG. 1, the above-mentioned layers are formed on a transparent substrate having insulating properties by a vacuum deposition method, a sputtering method, an ion plating method, a spin coating method, a printing method, or the like. Can be sequentially stacked.

  The organic solar cell A thus formed has a configuration in which a solar cell that generates power by absorbing an infrared light region and a solar cell that generates power by absorbing a visible light region are integrated.

  That is, when light is generated by taking in light from the electrode 2 on the first photoelectric conversion layer 1a side of the organic solar cell A, first, the incident light reaches the first photoelectric conversion layer 1a, and infrared light is absorbed. Power is generated. At this time, since the visible light absorption in the first photoelectric conversion layer 1a is small, most of the visible light passes through the first photoelectric conversion layer 1a. The transmitted visible light reaches the second photoelectric conversion layer 1b, and the visible light is absorbed to generate power.

  In this way, the first photoelectric conversion layer 1a can generate power using infrared light and the second photoelectric conversion layer 1b can generate power using visible light. At this time, the first photoelectric conversion layer 1a Since the visible light transmittance is high, the loss of visible light until reaching the second photoelectric conversion layer 1b is reduced, the power generation efficiency is improved, and the first photoelectric conversion layer 1a and the first photoelectric conversion layer 1 Since the second photoelectric conversion layer 1b is laminated, the power generation efficiency per area of the organic solar cell A is improved.

  Further, instead of the second photoelectric conversion layer 1b, a photoelectric conversion layer 1 (third photoelectric conversion layer 1c) having a light absorption peak in the ultraviolet region may be provided.

  The 3rd photoelectric converting layer 1c can be formed as what contains the semiconductor which has a light absorption peak in an ultraviolet-light area | region.

  A semiconductor having a light absorption peak in the ultraviolet light region has a large absorption peak in the ultraviolet light region and has no absorption in the visible light region and the infrared light region.

  As the third photoelectric conversion layer 1c, for example, a layer having a pn structure with an energy band gap of 3 eV or more can be provided. At this time, copper aluminum oxide, copper gallium oxide, copper indium oxide is used as the p layer. , Copper chromium oxide, copper scandium oxide, copper yttrium oxide, silver indium oxide, and a layer made of a p-type semiconductor selected from strontium copper oxide, and n layer tin oxide, indium oxide, titanium oxide, An n-type semiconductor selected from strontium titanate, zinc oxide, gallium nitride, and copper indium oxide can be provided.

  The organic solar cell A thus formed has a configuration in which a solar cell that generates power by absorbing an infrared light region and a solar cell that generates power by absorbing an ultraviolet light region are integrated.

  That is, when light is generated by taking in light from the electrode 2 on the first photoelectric conversion layer 1a side of the organic solar cell A, first, the incident light reaches the first photoelectric conversion layer 1a, and infrared light is absorbed. Power is generated. At this time, since the first photoelectric conversion layer 1a absorbs less ultraviolet light, most of the ultraviolet light passes through the first photoelectric conversion layer 1a. The transmitted ultraviolet light reaches the third photoelectric conversion layer 1c, and the ultraviolet light is absorbed to generate power.

  In this way, the first photoelectric conversion layer 1a can generate power using infrared light and the third photoelectric conversion layer 1c can generate power using ultraviolet light. At this time, the first photoelectric conversion layer 1a Since the transmittance of the ultraviolet light at is high, the loss of ultraviolet light until reaching the third photoelectric conversion layer 1c is reduced, the power generation efficiency is improved, and the first photoelectric conversion layer 1a and the first photoelectric conversion layer Since the third photoelectric conversion layer 1c is laminated, the power generation efficiency per area of the organic solar cell A is improved.

  Moreover, the organic solar cell A which has the some photoelectric converting layer 1 containing the above 1st photoelectric converting layers 1a other than what has the two layers of photoelectric converting layers 1 in this way can also be formed.

  In particular, an organic solar cell A having a configuration in which a laminate of a first photoelectric conversion layer 1a, a second photoelectric conversion layer 1b, and a third photoelectric conversion layer 1c is interposed between two electrodes 2 and 2. Then, power generation using infrared light in the first photoelectric conversion layer 1a, power generation using visible light in the second photoelectric conversion layer 1b, and power generation using ultraviolet light in the third photoelectric conversion layer 1c Thus, power generation can be performed using light in a wide wavelength range from the ultraviolet light region to the infrared light region, and the power generation efficiency is further improved.

  Further, the organic solar cell A having the above-described configuration is used as a photoelectric conversion unit, and an optical sensor can be configured by providing a detection unit that detects a change in electrical characteristics of the photoelectric conversion unit.

  The detection unit measures an electromotive force generated when the photoelectric conversion unit is irradiated with light to be detected, or the current-voltage characteristics of the photoelectric conversion unit when the photoelectric conversion unit is irradiated with light to be detected. Can be mentioned. Specifically, for example, when used as an infrared sensor, four photoelectric conversion units are bridge-connected, a light blocking structure is provided in two photoelectric conversion units facing each other, and the other two photoelectric conversion units facing each other are externally connected. A structure in which light is incident is provided, and a circuit capable of detecting a potential difference at an intermediate point is configured. In this case, when infrared light is not incident, the potential difference at the intermediate point is 0. However, when infrared light is incident, the resistance value changes only in the photoelectric conversion unit that is not shielded, and a potential difference is generated at the intermediate point. Based on this, infrared light can be detected.

  Such an optical sensor can be used, for example, as an optical communication receiver using infrared light or an infrared transparent light sensor.

  Next, the present invention will be specifically described with reference to examples.

[Example 1]
A PEDOT: PSS layer (poly [3,4- (ethylenedioxy) thiophene]: poly (styrene) is formed as a buffer layer (hole transport layer) on a glass substrate on which an ITO thin film having a thickness of 150 nm is formed as the electrode 2. sulfonate)) with a film thickness of 25 nm.

  As an organic semiconductor having an absorption peak of light in the infrared region, copper (II) 5, 9, 14, 18, 23, 27, 32, 36-octabutoxy-2,3-na represented by the above formula (2) is used. Since phthalocyanine (Obu-CunaPc) was used and this Obu-CunaPc is soluble in an organic solvent, it was spin-coated on the hole transport layer to form a 25 nm thick layer of Obu-CunaPc.

  Next, fullerene (C60) was vacuum-deposited as a light-transmitting n-type semiconductor to form a layer made of light-transmitting fullerene (C60) with a film thickness of 25 nm.

  Thereafter, a BCP (bathocupline) is formed as a buffer layer (electron transport layer) with a thickness of 5 nm, and finally an Mg: Ag alloy thin film is formed as an electrode 22 with a thickness of 100 nm. Obtained. This organic solar cell A was transparent.

[Example 2]
On the glass substrate on which the ITO thin film is formed with a film thickness of 150 nm as the electrode 2, first, a layer made of zinc phthalocyanine represented by the formula (4) is formed as a p layer by vapor deposition so as to have a thickness of 5 nm. Next, by co-evaporation, a layer obtained by blending zinc phthalocyanine and fullerene (C60) at a volume ratio of 1: 1 as an i layer is formed to a thickness of 15 nm, and then a layer made of fullerene (C60) is formed as an n layer to a thickness of 30 nm Thus, the second photoelectric conversion layer 1b having a pin structure was formed.

  Next, BCP (bathocupline) was formed to a thickness of 5 nm as a buffer layer (electron transport layer).

  Next, after depositing Ag to a thickness of 5 nm, ITO was deposited to a thickness of 20 nm to form the intermediate electrode 4.

  Next, the buffer layer (hole transport layer), the photoelectric conversion layer 1 (first photoelectric conversion layer 1a), the buffer layer (electron transport layer), and the electrode 2 were sequentially formed in the same manner as in Example 1. An organic solar cell A was obtained.

  Although this organic solar cell A has low transparency, it has a form in which a solar cell that absorbs the infrared light region to generate power and a solar cell that absorbs the visible light region to generate power and has a high conversion efficiency. Is obtained.

[Comparative Example 1]
An organic solar cell A was obtained in the same manner as in Example 1 except that copper phthalocyanine represented by the formula (4) was used as the organic semiconductor.

(Semiconductor absorption spectrum)
The absorption spectrum of light was measured for each of Obu-CunaPc used in Example 1 and phthalocyanine used in Comparative Example 1. The result is shown in FIG. In addition, the vertical axis | shaft in FIG. 3 shows the normalized light absorbency.

  Phthalocyanine has an absorption peak in the visible light region and has a low absorbance in the infrared light region, whereas Obu-CunaPc has an absorption peak in the infrared light region near 870 nm and a low absorbance in the visible light region. there were.

(Solar cell characteristics evaluation)
About the organic solar cell A of Example 1, AM1.5G, 100 mW / cm < ² > pseudo-sunlight (Air Mass 1.5 Global 100 mW / cm < ² >) was irradiated with the solar simulator, and the current of the organic solar cell A in this state -The drive as a solar cell was confirmed by measuring the voltage characteristics and deriving the solar cell parameter of the short-circuit photocurrent (Jsc).

  In FIG. 4, the result of having measured the electric current-voltage characteristic of the organic solar cell A of Example 1 about each of the state which is irradiating pseudo sunlight, and the state which is not irradiating is shown. Thereby, the organic solar cell A of Example 1 was light-responsive at the time of pseudo-sunlight irradiation, and has confirmed that it was driving as a solar cell.

The solar cell parameter was Jsc = 0.58 mA / cm ² , confirming that it was functioning as a solar cell.

  In addition, it is expected that by improving the purity of the material, optimizing the structure of the solar cell device, etc., the value of the solar cell parameter can be increased to further improve the performance.

(Spectral sensitivity measurement)
About the organic solar cell A of Example 1 and Comparative Example 1, the monochromatic light is irradiated with single wavelength light that is changed in increments of 5 nm within a range of 300 to 1000 nm, and light generated in the organic solar cell A for each wavelength. The spectral sensitivity was measured by measuring the current. The result is shown in FIG. In addition, the vertical axis | shaft in FIG. 5 shows the normalized spectral sensitivity.

  The spectral sensitivity of the organic solar cell A of Example 1 was highly correlated with the absorption spectrum of Obu-CunaPc, and was driven in the infrared region. In contrast, the organic solar cell A of Comparative Example 1 was driven in the visible light region but not in the infrared light region.

It is sectional drawing which shows an example of embodiment of this invention. It is sectional drawing which shows the other example of embodiment of this invention. It is a graph which shows the result of having measured the optical absorption spectrum about each of Obu-CunaPc used in Example 1, and the phthalocyanine used in the comparative example 1. FIG. It is a graph which shows the measurement result of the current-voltage characteristic of the organic solar cell of Example 1 and Comparative Example 1. It is a graph which shows the measurement result about the spectral sensitivity about the organic solar cell of Example 1 and Comparative Example 1.

Explanation of symbols

A Organic solar cell 1 Photoelectric conversion layer 2 Electrode

Claims (6)

  An organic solar cell, wherein a photoelectric conversion layer containing an organic semiconductor having a light absorption peak in an infrared region is provided between two electrodes.   The two electrodes are both transparent electrodes, and the photoelectric conversion layer disposed between the two electrodes is only the photoelectric conversion layer containing an organic semiconductor having a light absorption peak in the infrared light region. The organic solar cell according to claim 1, wherein the organic solar cell is provided.   A plurality of layers including a photoelectric conversion layer containing an organic semiconductor having a light absorption peak in an infrared light region and a photoelectric conversion layer having a light absorption peak in a visible light region or an ultraviolet light region between the two electrodes. The organic solar cell according to claim 1, wherein the photoelectric conversion layer is provided by being laminated via a light-transmitting intermediate electrode.   The photoelectric conversion layer containing an organic semiconductor having an absorption peak of light in an infrared light region contains an n-type semiconductor having optical transparency, and the organic semiconductor and the n-type semiconductor are in contact in the photoelectric conversion layer. The organic solar cell according to claim 1, wherein the organic solar cell is a solar cell.   The organic solar cell according to any one of claims 1 to 4, wherein the organic semiconductor having a light absorption peak in the infrared light region is naphthalocyanine or a naphthalocyanine derivative.   An optical sensor comprising: a photoelectric conversion unit including the organic solar battery according to claim 1; and a detection unit that detects a change in electrical characteristics of the photoelectric conversion unit.

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