CN103094269B - White light emitting device and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of tool to change through fluorescent material and be the white light emitting device of active illuminating, the mixed light emitting source of inorganic light-emitting diode and the light emitting source of Organic Light Emitting Diode, both do electrical combination with parallel way.The bottom is Organic Light Emitting Diode, inorganic light-emitting diode is stacked and placed on Organic Light Emitting Diode, described inorganic light-emitting diode comprises the integer of n(n >=1) individual separate unit, voltage matches time in parallel with Organic Light Emitting Diode, thus reach more high efficiency and active white light source.

Description

White light emitting device and manufacturing method thereof

technical field

The invention relates to a semiconductor light emitting device, in particular to a hybrid white light emitting device and a manufacturing method thereof.

Background technique

With the rapid development of solid-state lighting applications, the most important thing is how to emit white light. In the wavelength range of 380nm to 760nm of the visible light spectrum, there is no white light spectrum in this range, because white light is not a single wavelength of light, but consists of multiple wavelengths. Just as sunlight is white light synthesized from seven monochromatic lights, and white light in a color TV is also synthesized from the three primary colors red, green, and blue. It can be seen from this that in order for a light-emitting device to emit white light, its spectral characteristics should include the entire visible spectral range. However, it is impossible to manufacture light-emitting devices with this performance under the current process conditions. According to people's research on visible light, white light that can be seen by human eyes requires at least a mixture of two kinds of light, that is, two-wavelength light (blue light + yellow light), that is, the commonly used blue light source plus yellow phosphor or Three-wavelength light emitting (blue light + green light + red light) mode, there are also short-wavelength ultraviolet light sources plus blue, green, and red three-color phosphors.

In addition, the commonly used blue light source plus inorganic yellow phosphor or short-wavelength ultraviolet light source plus inorganic blue, green, and red three-color phosphors, in the process of converting into white light, the absorption and absorption of the phosphor itself must be considered. The conversion efficiency and the phosphor itself is not an active light source, so the white light conversion efficiency must depend on the quality of the phosphor.

As shown in Figure 1, it is a conventional white light emitting device, which includes: a growth substrate 110; an N-type gallium nitride-based epitaxial stack 121, a light-emitting layer 122, a P-type gallium nitride-based epitaxial stack 123, a transparent Conductive layer 130 , P electrode 140 , N electrode 141 and fluorescent glue 150 .

Contents of the invention

The invention provides a white light-emitting device that does not need to be converted by phosphor powder and is active light-emitting. The light-emitting source of the inorganic light-emitting diode is mixed with the light-emitting source of the organic light-emitting diode, and the two are connected together to achieve higher efficiency and active. white light source.

Inorganic light-emitting diodes and organic light-emitting diodes are electrically connected in parallel. The bottom layer is organic light-emitting diodes, and the inorganic light-emitting diodes are stacked on top of the organic light-emitting diodes. The inorganic light-emitting diodes include n (n ≥ 1 integer ) independent unit, which matches the voltage when connected in parallel with an organic light-emitting diode, thereby emitting white light.

The inorganic light-emitting diode includes n (an integer of n≥2) independent units and is electrically connected in series.

The electrical connection method between the inorganic light emitting diode and the organic light emitting diode is as follows: the inorganic light emitting diode is divided into m (an integer of m≥2) modules, and each inorganic light emitting diode module is an independent unit or a plurality of independent units formed in series, and the m modules are electrically combined with the organic light emitting diodes in parallel.

The m (an integer of m≥2) modules composed of inorganic light emitting diodes can be used as point light sources and integrated on the first substrate, while the organic light emitting diodes can be used as a surface light source and share the first substrate with the inorganic light emitting diodes.

The size of the white light emitting device is consistent with the size of the first substrate.

The size of the same substrate can be 2 inches or 4 inches or 6 inches or 8 inches and above.

Inorganic light-emitting diodes, including: a first substrate, which has a first surface and a second surface; an N-type III-V group-based epitaxial stack, an active light-emitting layer, and a P-type III-V-based epitaxial stack, which are sequentially formed on on the first surface of the first substrate.

In some embodiments, the emission wavelength of the inorganic light emitting diode is between 200nm and 700nm.

In some embodiments, the organic light-emitting diode has one or more active light-emitting layers, and has one or more light-emitting wavelengths, which do not overlap with the wavelengths of the inorganic light-emitting diodes.

In some embodiments, the way of emitting white light is achieved by combining 440nm-470nm blue inorganic light-emitting diodes with 530-560nm green light and 610nm-640nm red light organic light-emitting diodes.

In some embodiments, the way of emitting white light is achieved by combining 530-560nm green inorganic light emitting diodes with 440nm-470nm blue light and 610nm-640nm red light organic light-emitting diodes.

In some embodiments, the way of emitting white light is achieved by combining 610nm-640nm red inorganic light-emitting diodes with 440nm-470nm blue light and 530-560nm green organic light-emitting diodes.

In some embodiments, the way of emitting white light is achieved by combining 200nm-400nm ultraviolet inorganic light-emitting diodes with 440nm-470nm blue light, 530-560nm green light and 610nm-640nm red light organic light-emitting diodes.

In some embodiments, the light-transmitting growth substrate is a sapphire growth substrate or a silicon carbide growth substrate.

In some embodiments, the transparent conductive layer is ITO, IWO or IZO.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

FIG. 1 is a schematic structural diagram of an existing white light emitting device.

Fig. 2 is a schematic structural diagram of a front-mounted white light emitting device according to Embodiment 1 of the present invention.

3 to 9 are schematic cross-sectional views of the fabrication process of the front-mounted white light emitting device shown in FIG. 2 .

Fig. 10 is a schematic structural diagram of a flip-chip white light emitting device according to Embodiment 2 of the present invention.

11 to 18 are schematic cross-sectional views of the manufacturing process of the flip-chip white light emitting device shown in FIG. 10 .

FIG. 19 is a top view of the manufacturing process of the flip-chip white light emitting device shown in FIG. 2 .

Each label in the figure means:

110, 210, 310: first substrate (growth substrate);

121, 221, 321: N-type GaN-based epitaxial stacks;

122, 222, 322: light-emitting layer;

123, 223, 323: P-type gallium nitride-based epitaxial stack;

130, 230, 330: transparent conductive layer;

140, 240, 340: P electrodes;

141, 241, 341: N electrode;

150: fluorescent glue;

250, 350: insulating protective layer;

260, 360: internal PN wire connection layer;

261, 361: positive connection layer;

262, 362: Negative connection layer;

270, 370: anode of organic light emitting device;

280, 380: organic light-emitting layer;

290, 390: organic light-emitting device cathode;

410: the second substrate (insulating substrate).

detailed description

The structure of the white light emitting device of the present invention and its manufacturing method will be described in more detail below in conjunction with schematic diagrams, wherein a preferred embodiment of the present invention is shown. It should be understood that those skilled in the art can modify the present invention described here and still realize the present invention. Beneficial effects of the invention. Therefore, the following description should be understood as the broad knowledge of those skilled in the art, but not as a limitation of the present invention.

The following embodiments disclose white light emitting devices and manufacturing methods thereof, wherein the manufacturing methods of white light emitting devices include manufacturing steps of inorganic light emitting diodes and organic light emitting diodes.

Manufacturing steps of inorganic light-emitting diodes:

(1) For inorganic light-emitting diodes, a III-V group-based light-emitting epitaxial stack is formed on the first surface of the light-transmitting growth substrate, including a III-V-based N-type epitaxial stack, an active light-emitting layer, and a III-V group-based epitaxial stack. Group V-based P-type epitaxial stack;

(2) In this device, n independent units can be formed by wet etching or dry etching, and then connected in series or in parallel through metal wiring.

Manufacturing steps of organic light-emitting diodes and parallel connection:

(1) In the formal white light-emitting device, the transparent anode, the hole transport layer, the active light-emitting layer, the electron transport layer, and the reflective cathode are directly vapor-deposited on the second surface of the first substrate in sequence, and then the transparent The positive anode is connected to the P-type area of the inorganic light-emitting diode, and the reflective cathode is connected to the N-type area of the inorganic light-emitting diode;

(2) In the flip-chip white light-emitting device, the transparent anode, the hole transport layer, the active light-emitting layer, the electron transport layer, and the reflective cathode are vapor-deposited on the second substrate in sequence, and then the inorganic light-emitting diode is inverted and The organic light-emitting diode evaporated on the second substrate is connected in parallel, the transparent anode is connected with the P-type area of the inorganic light-emitting diode, and the reflective cathode is connected with the N-type area of the inorganic light-emitting diode.

In white light-emitting devices, the wavelength matching forms of inorganic light-emitting diodes and organic light-emitting diodes used to mix and emit white light can be as follows:

(1) White light is formed by combining 440nm~470nm blue inorganic light emitting diodes with 530~560nm green light and 610nm~640nm red light organic light emitting diodes.

(2) White light is formed by combining 530-560nm green inorganic light-emitting diodes with 440nm-470nm blue light and 610nm-640nm red light organic light-emitting diodes.

(3) The formation of white light is achieved by combining 610nm~640nm red light inorganic light emitting diodes with 440nm~470nm blue light and 530~560nm green light organic light emitting diodes.

(4) White light is formed by combining 200nm~400nm ultraviolet inorganic light emitting diodes with 440nm~470nm blue light, 530~560nm green light and 610nm~640nm red light organic light emitting diodes.

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

Figure 2 shows a front-mounted white light emitting device, which includes from bottom to top: an organic light emitting device cathode 270, an organic light emitting layer 280, an organic light emitting device anode 290, a first substrate 210, and an N-type GaN-based epitaxial stack Layer 221, light-emitting layer 222, P-type GaN-based epitaxial stack 223, transparent conductive layer 230, P electrode 240, N electrode 241, insulating protection layer 250, internal PN wire connection layer 260, positive connection layer 261, negative connection Layer 262.

The manufacturing process of the above-mentioned front-mounted white light emitting device specifically includes the following steps.

As shown in FIG. 3 , first provide a first substrate 210, such as a light-transmitting sapphire substrate, and form an N-type GaN-based semiconductor layer 221, a light-emitting layer 222, and a P-type GaN-based epitaxial stack on the first surface. 223, a transparent conductive layer 230, such as ITO.

As shown in FIG. 4 , the platform is formed by dry etching.

As shown in FIG. 5 , n (integer of n≥2) independent units are formed by dry etching.

As shown in FIG. 6 , the insulating protective layer 250 is formed by chemical vapor deposition (CVD), and the pattern of the insulating protective layer is defined by yellow light and wet etching.

As shown in FIG. 7 , a P electrode 240 , an N electrode 241 , and an internal PN wire connection layer 260 are defined by yellow light and physical vapor deposition (PVD) to form an internal serial connection.

As shown in FIG. 8 , an organic light-emitting device anode 270 , an organic light-emitting layer 280 , and an organic light-emitting device cathode 290 are sequentially formed on the second surface of the first substrate 210 by means of physical vapor deposition (PVD), wherein the anode 270 is composed of light-transmitting Sexual material composition.

As shown in FIG. 9 , the positive connection layer 261 is formed by physical vapor deposition (PVD), and the P electrode 240 is connected to the anode 270 of the organic light-emitting device; the negative connection layer 262 is formed by physical vapor deposition (PVD), and the N electrode 241 is connected to the cathode 290 of the organic light-emitting device, so far a formal white light-emitting device is formed. Through the matching of the wavelengths of the inorganic light-emitting diode device and the organic light-emitting diode device, a white light source can be deployed and this light source is not achieved by light conversion, so Without any light loss in the process of light conversion, more efficient white light devices can be manufactured.

Example 2

Figure 10 shows a flip-chip white light-emitting device, which includes from bottom to top: a second substrate 410, an organic light-emitting device anode 370, an organic light-emitting layer 380, an organic light-emitting device cathode 390, a positive connection layer 361, and a negative electrode Connection layer 362, P electrode 340, N electrode 341, internal PN wire connection layer 360, insulating protection layer 350, transparent conductive layer 330, P-type GaN-based epitaxial stack 323, light-emitting layer 322, N-type GaN-based Epitaxial stack 321 , growth substrate 310 .

The manufacturing process of the above flip-chip white light emitting device specifically includes the following steps.

As shown in FIG. 11 , first provide a first substrate (growth substrate) 310, such as a silicon carbide substrate, and form an N-type gallium nitride-based semiconductor layer 321, a light-emitting layer 322, and a P-type gallium nitride-based semiconductor layer on the first surface. Epitaxial stack 323 and transparent conductive layer 330, such as IZO.

As shown in FIG. 12 , the platform is formed by dry etching.

As shown in FIG. 13 , n independent units are formed by wet etching.

As shown in FIG. 14 , the insulating protective layer 350 is formed by chemical vapor deposition (CVD), and the pattern of the insulating protective layer is defined by yellow light and wet etching.

As shown in FIG. 15 , a P electrode 340 , an N electrode 341 , and an internal PN wire connection layer 360 are defined by yellow light and physical vapor deposition (PVD) to form an internal serial connection.

As shown in FIG. 16, the first substrate 310 is thinned and turned upside down.

As shown in FIG. 17 , the organic light-emitting device cathode 390, the organic light-emitting layer 380, and the organic light-emitting device anode 370 are sequentially formed on the second substrate (insulating substrate) 410 by physical vapor deposition (PVD), and the organic light-emitting device anode 370 is formed by physical vapor deposition The anode connection layer 361 and the anode connection layer 362 are formed by (PVD) method, wherein the organic light-emitting layer 380 includes a hole transport layer, an active light-emitting layer, and an electron transport layer.

As shown in FIG. 18, the P electrode 340 is connected to the anode 370 of the machine light-emitting device through the positive connection layer 361 by using an inverted die-bonding method; The cathode 390 of the device is connected, and the manufacture of the flip-chip white light-emitting device is completed. By matching the wavelengths of the inorganic light-emitting diode device and the organic light-emitting diode device, a white light source can be deployed, and this light source is not achieved by light conversion, so there is no Light loss in the process of light conversion enables the manufacture of more efficient white light devices.

Example 3

The difference between this embodiment and Embodiment 1 is that the inorganic light emitting diodes are divided into multiple modules, and each module can be formed as an independent unit or a plurality of independent units connected in series. As shown in Figure 19, the same number of n (an integer of n≥2) independent unit inorganic light-emitting diodes are connected in series to form two modules, and the two modules are connected with organic light-emitting diodes (not shown in the figure) Do parallel electrical connection.

In this embodiment, the two modules composed of the above-mentioned inorganic light emitting diodes are used as point light sources, and are formed on the first substrate 210 in an integrated manner, while the organic light emitting diodes are used as a surface light source, sharing the first light source with the inorganic light emitting diodes. Substrate 210.

The size of the white light emitting device formed in this embodiment is consistent with the size of the first substrate, and the size of the first substrate 210 is 4 inches.

Example 4

The difference between this embodiment and embodiment 2 is that: the LED chips are prepared first, and then the LED chips are placed on the organic light-emitting diodes according to grains by using a rotating disk suction device, and connected by a die-bonding method.

Specifically, it may be as follows: firstly, a series of LED chips are prepared by adopting conventional LED chip technology. Next, the cathode 390 of the organic light-emitting device, the organic light-emitting layer 380, and the anode 370 of the organic light-emitting device are sequentially formed on the insulating substrate 410 by physical vapor deposition (PVD), and the positive connection layer 361 and the positive electrode connection layer are formed by physical vapor deposition (PVD). The negative connection layer 362, wherein the organic light-emitting layer 380 includes a hole transport layer, an active light-emitting layer, and an electron transport layer. Then, the LED chips are placed on the organic light-emitting diodes by using a rotating disk suction device, and connected by a crystal-bonding method.

This embodiment is suitable for large-sized surface light sources, and the area of the insulating substrate can be set according to application requirements.

Claims (13)

1. white light emitting device, comprise: inorganic light-emitting diode and Organic Light Emitting Diode, both do electrical combination with parallel way, it is characterized in that: described inorganic light-emitting diode is stacked and placed on described Organic Light Emitting Diode, described inorganic light-emitting diode comprises n separate unit, and it is electrically connected mode for series connection; The electric connection mode of described inorganic light-emitting diode and Organic Light Emitting Diode is: described inorganic light-emitting diode is divided into m module, each inorganic light-emitting diode module is that a separate unit or multiple separate unit are in series, and a described m module and Organic Light Emitting Diode do and in parallelly electrically to combine; When after device energising, excited inorganic light-emitting diode and organic diode luminescence, m the module that inorganic light-emitting diode is formed is as point-source of light, and Organic Light Emitting Diode is as an area source, one first substrate is shared with described inorganic light-emitting diode, both mix thus send white light, and wherein n is integer and n >=2, and m is integer and m >=2.

2. white light emitting device according to claim 1, is characterized in that: the described inorganic light-emitting diode form in parallel with Organic Light Emitting Diode is direct in parallel or upside-down mounting parallel form.

3. white light emitting device according to claim 2, is characterized in that: described first substrate, and it has first surface and second surface; Described inorganic light-emitting diode is formed on first surface, and described Organic Light Emitting Diode is formed on second surface.

4. white light emitting device according to claim 2, it is characterized in that: described Organic Light Emitting Diode also comprises the second substrate, it has first surface and second surface, described Organic Light Emitting Diode is formed on first surface, and described inorganic light-emitting diode upside-down mounting is formed on described Organic Light Emitting Diode.

5. white light emitting device according to claim 1, is characterized in that: described Organic Light Emitting Diode has one or more active illuminating layer, and the one or more emission wavelength of tool, its not with inorganic light-emitting diode overlapping wavelengths.

6. white light emitting device according to claim 5, is characterized in that: the mode that described white light emitting device sends white light is that 440nm ~ 470nm blue light inorganic light-emitting diode collocation 530 ~ 560nm green glow and 610nm ~ 640nm ruddiness Organic Light Emitting Diode are reached.

7. white light emitting device according to claim 5, is characterized in that: the mode that described white light emitting device sends white light is that 530 ~ 560nm green glow inorganic light-emitting diode collocation 440nm ~ 470nm blue light and 610nm ~ 640nm ruddiness Organic Light Emitting Diode are reached.

8. white light emitting device according to claim 5, is characterized in that: the mode that described white light emitting device sends white light is that 610nm ~ 640nm ruddiness inorganic light-emitting diode collocation 440nm ~ 470nm blue light and 530 ~ 560nm green glow Organic Light Emitting Diode are reached.

9. white light emitting device according to claim 5, is characterized in that: the mode that described white light emitting device sends white light is that 200nm ~ 400nm ultraviolet light inorganic light-emitting diode collocation 440nm ~ 470nm blue light, 530 ~ 560nm green glow and 610nm ~ 640nm ruddiness Organic Light Emitting Diode are reached.

10. the manufacture method of white light emitting device, comprises step:

1) make inorganic light-emitting diode and Organic Light Emitting Diode respectively, wherein said inorganic light-emitting diode is stacked and placed on described Organic Light Emitting Diode, and described inorganic light-emitting diode comprises n separate unit, and it is electrically connected mode for series connection; The electric connection mode of described inorganic light-emitting diode and Organic Light Emitting Diode is: described inorganic light-emitting diode is divided into m module, each inorganic light-emitting diode module is that a separate unit or multiple separate unit are in series, a described m module and Organic Light Emitting Diode do and in parallelly electrically to combine, wherein n is integer and n >=2, and m is integer and m >=2;

2) described inorganic light-emitting diode and described Organic Light Emitting Diode is connected in parallel, when after device energising, excited inorganic light-emitting diode and organic diode luminescence, m the module that inorganic light-emitting diode is formed is as point-source of light, and Organic Light Emitting Diode is as an area source, share a substrate with described inorganic light-emitting diode, both mix thus send white light, and wherein m is integer and m >=2.

The manufacture method of 11. white light emitting devices according to claim 10, described step 1) comprises:

There is provided the first substrate, it has two surfaces;

At the first surface Epitaxial growth N type semiconductor material layer of described first substrate, active illuminating layer and P type semiconductor material layer, form inorganic light-emitting diode;

On the second surface of described first substrate, direct the evaporation transparency anode, electric hole transport layer, active illuminating layer, electron transfer layer and reflective negative electrode, be formed with OLED.

The manufacture method of 12. white light emitting devices according to claim 10, described step 1) comprises:

There is provided the first substrate, it has two surfaces, at the first surface Epitaxial growth N type semiconductor material layer of described first substrate, active illuminating layer and P type semiconductor material layer, forms inorganic light-emitting diode;

There is provided the second substrate, it has two surfaces, on the first surface of described second substrate successively evaporation the transparency anode, electric hole transport layer, active illuminating layer, electron transfer layer, reflective negative electrode, be formed with OLED;

Described inorganic light-emitting diode upside-down mounting is placed on described Organic Light Emitting Diode.

The manufacture method of 13. white light emitting devices according to claim 11 or 12, described step 2) be: done with the P type semiconductor material layer of inorganic light-emitting diode by the transparent anode of described Organic Light Emitting Diode and be connected, reflective negative electrode does with the N type semiconductor material layer of inorganic light-emitting diode and is connected.