CN101964366A - Photoelectric conversion element - Google Patents

Abstract

The present invention relates to a photoelectric conversion element, which is suitable for converting a light into a photocurrent. The aforementioned photoelectric conversion element includes a photoelectric conversion layer, a top conductive layer and a bottom conductive layer. The photoelectric conversion layer has a bottom plane, a top plane relative to the bottom plane, and a light incident side surface connected between the bottom plane and the top plane, wherein the angle between the bottom plane and the light incident side surface is θ, and 64°≤θ≤79°. The top conductive layer is arranged on the top plane of the photoelectric conversion layer, and the bottom conductive layer is arranged below the bottom plane of the photoelectric conversion layer.

Description

Photoelectric conversion element

technical field

The present invention relates to a photoelectric conversion element, and in particular to a vertical type photoelectric conversion element.

Background technique

In recent years, photoelectric conversion elements such as solar cells and photosensors have been widely used in human living environments. With the issue of environmental protection and energy saving, solar cells have become the most potential green alternative energy, and light sensors have been applied in flat panel displays. Through the light sensor, the flat panel display can detect the intensity of external light to adjust the brightness of the display. In addition, the light sensor enables the flat panel display to have a touch function and/or a scanning function, making the flat panel display more multifunctional.

On the substrate, the photoelectric conversion elements can be roughly divided into two types according to their structures: one is a horizontal photoelectric conversion element, and the other is a vertical photoelectric conversion element. Compared with the vertical photoelectric conversion element, the process of the horizontal photoelectric conversion element is more complicated, but because the light is easier to irradiate the light conversion layer of the horizontal photoelectric conversion element, the horizontal photoelectric conversion element has better sensitivity and photoelectric conversion. efficiency. The process of the vertical photoelectric conversion element is relatively simple, but since light is less likely to irradiate the light conversion layer of the vertical photoelectric conversion element, the sensitivity and photoelectric conversion efficiency of the vertical photoelectric conversion element are poor. Therefore, how to improve the sensitivity and photoelectric conversion efficiency of the vertical photoelectric conversion element is one of the problems that those skilled in the art want to solve urgently.

Contents of the invention

The invention provides a photoelectric conversion element, the phototransformation layer of which has an inclined light incident side to effectively improve sensitivity and photoelectric conversion efficiency.

The invention provides a photoelectric conversion element suitable for converting a light into a photocurrent. The aforementioned photoelectric conversion element includes a photo conversion layer, a top conductive layer and a bottom conductive layer. The light conversion layer has a bottom plane, a top plane relative to the bottom plane, and a light incident side connected between the bottom plane and the top plane, wherein the angle between the bottom plane and the light incident side is θ, and 64°≤θ ≤79°. The top conductive layer is configured on the top plane of the light conversion layer, and the bottom conductive layer is configured under the bottom plane of the light conversion layer.

In an embodiment of the present invention, the incident angle of the light incident on the aforementioned light incident side is θ _i , and θ is equal to θ _i .

In an embodiment of the present invention, the aforementioned light conversion layer is, for example, an intrinsic semiconductor layer.

In an embodiment of the present invention, the aforementioned light conversion layer is, for example, an amorphous silicon layer, a microcrystalline silicon layer, a polysilicon layer, an epitaxial silicon layer, a silicon-rich material layer, a silicon germanium layer, a gallium Arsenic layers or stacks thereof.

In an embodiment of the present invention, the aforementioned photoelectric conversion element may further include a first-type doped semiconductor layer and a second-type doped semiconductor layer, wherein the first-type doped semiconductor layer is disposed between the bottom conductive layer and the optical between the conversion layers, and the second-type doped semiconductor layer is disposed between the top conductive layer and the light conversion layer.

In an embodiment of the present invention, when the first-type doped semiconductor layer is an N-type doped semiconductor layer, the second-type doped semiconductor layer is a P-type doped semiconductor layer. Conversely, when the first-type doped semiconductor layer is a P-type doped semiconductor layer, the second-type doped semiconductor layer is an N-type doped semiconductor layer.

In an embodiment of the present invention, the aforementioned photoelectric conversion element may further include a reflective layer disposed between the first-type doped semiconductor layer and the bottom conductive layer.

In an embodiment of the present invention, the aforementioned top conductive layer has a rough surface, and the rough surface is not in contact with the top plane of the light conversion layer.

In an embodiment of the present invention, 75°≤θ≤79°.

In an embodiment of the present invention, the aforementioned photoelectric conversion element may further include a protective layer to cover the light incident side.

In an embodiment of the present invention, the aforementioned protection layer is made of silicon nitride or silicon oxide, for example. Furthermore, when the light incident side is covered with a protective layer, 64°≦θ≦69°.

In an embodiment of the present invention, the shapes of the aforementioned bottom plane and top plane are polygonal, circular or elliptical.

In an embodiment of the present invention, the aforementioned top conductive layer is a transparent conductive layer, and the bottom conductive layer is a reflective conductive layer.

Since the light conversion layer in the photoelectric conversion device of the present invention has an inclined light incident side, the photoelectric conversion device of the present invention has good sensitivity and photoelectric conversion efficiency.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

Description of drawings

In order to make the above and other objects, features, advantages and embodiments of the present invention more comprehensible, the accompanying drawings are described as follows:

FIG. 1 is a schematic perspective view of a photoelectric conversion element according to an embodiment of the present invention;

2A to 5A and 2B to 5B are schematic cross-sectional views of photoelectric conversion elements according to different embodiments of the present invention.

Among them, reference signs

100, 100a～100f: photoelectric conversion element 110: light conversion layer

110a: Bottom plane 110b: Top plane

110c: Light incident side 120: Bottom conductive layer

130: top conductive layer 130a: rough surface

140: Type 1 doped semiconductor layer 150: Type 2 doped semiconductor layer

160: Protective layer 170: Reflective layer

θ _i : angle of incidence θ _r : angle of refraction

θ: Angle L: Light

R: reflected light

Detailed ways

1 is a schematic perspective view of a photoelectric conversion device according to an embodiment of the present invention, and FIGS. 2A to 5A and 2B to 5B are cross-sectional schematic views of photoelectric conversion devices according to different embodiments of the present invention.

Referring to FIG. 1 and FIG. 2A , the photoelectric conversion element 100 of this embodiment is suitable for converting a light L into a photocurrent. The photoelectric conversion device 100 of this embodiment includes a photo conversion layer 110 , a bottom conductive layer 120 and a top conductive layer 130 . The light conversion layer 110 has a bottom plane 110a, a top plane 110b opposite to the bottom plane 110a, and a light incident side 110c connected between the bottom plane 110a and the top plane 110b, wherein the bottom plane 110a and the light incident side 110c sandwich The angle is θ, and 64°≤θ≤79°. The bottom conductive layer 120 is disposed on the bottom plane 110 a of the light conversion layer 110 , and the top conductive layer 130 is disposed under the top plane 110 b of the light conversion layer 110 .

In this embodiment, the shape of the bottom plane 110a and the top plane 110b is rectangular. Of course, in other feasible embodiments. The bottom plane 110 a and the top plane 110 b can be polygonal (such as triangle, pentagon, hexagon, etc.), circle, ellipse, ring or multiple rings of concentric circles. In addition, the top conductive layer 130 of this embodiment is, for example, a transparent conductive layer to facilitate light L to pass through and irradiate on the light conversion layer 110, and the bottom conductive layer 120 is, for example, a reflective conductive layer to reflect light L back to the light conversion layer. 110.

In this embodiment, the light conversion layer 110 is, for example, an intrinsic semiconductor layer, and the light conversion layer 110 is, for example, an amorphous silicon layer, a microcrystalline silicon layer, a polysilicon layer, an epitaxial silicon layer, a silicon-rich material layer, a silicon germanium layer, a gallium arsenic layer or a stack thereof. When the light conversion layer 110 is composed of an intrinsic semiconductor layer, the photoelectric conversion element 100 can be used as a photosensor. Of course, this embodiment does not limit the material and type of the light conversion layer 110 , and the light conversion layer 110 may be made of other materials or have other types.

In other feasible embodiments, in order to further improve the photoelectric conversion efficiency of the photoelectric conversion element 100, the photoelectric conversion element 100 may further include a first-type doped semiconductor layer 140 and a second-type doped semiconductor layer 150, wherein the first The type doped semiconductor layer 140 is disposed between the top conductive layer 130 and the light conversion layer 110 , and the second type doped semiconductor layer 150 is disposed between the bottom conductive layer 120 and the light conversion layer 110 . For example, when the first-type doped semiconductor layer 140 is an N-type doped semiconductor layer, the second-type doped semiconductor layer 150 is a P-type doped semiconductor layer. On the contrary, when the first-type doped semiconductor layer 140 is a P-type doped semiconductor layer, the second-type doped semiconductor layer 150 is an N-type doped semiconductor layer. When the photoelectric conversion element 100 includes the first-type doped semiconductor layer 140 and the second-type doped semiconductor layer 150 , the photoelectric conversion element 100 can be used as a solar cell. It should be noted that the first-type doped semiconductor layer 140 and the second-type doped semiconductor layer 150 are optional components in the photoelectric conversion element 100, and those skilled in the art can selectively fabricate the first-type doped semiconductor layer according to product design requirements. The hetero semiconductor layer 140 and the second type doped semiconductor layer 150 .

In order to make the light L incident into the light conversion layer 110 smoothly, in this embodiment, the bottom plane 110 a and the light incident side surface 110 c form an angle θ, which is preferably 64°≦θ≦79°. Wherein, the included angle θ is equal to the incident angle θ _i of the light L incident on the light incident side surface 110 c. In detail, the included angle θ better conforms to the definition of Brewster's angle, when the sum of the incident angle θ _i and the refraction angle θ _r of light L is π/2 (ie θ _i + θ _r = π/ 2), the proportion of the reflected light R is close to 0, and the proportion of the light L entering the light conversion layer 110 from the light incident side 110c is close to 100%. Assuming that light is incident from a medium with a refractive index of n1 to the light conversion layer 110 with a refractive index of n2, when the incident angle θ _i satisfies the condition of Brewster's angle (ie θ _i + θ _r = π/2), it can be deduced from the following formula The included angle θ is equal to the incident angle θ _i .

n1·sinθ _i ＝n2·sinθ _r

→n1·sinθ _i ＝n2·sin(π/2-θ _i )

→n1·sinθ _i =n2·cosθ _i

→ _θi = tan ^-1 (n2/n1) = θ

Generally speaking, when the light L is directly incident on the light conversion layer 110 from the air, the included angle θ is between 75° and 79°. Since the included angle θ conforms to the condition of Brewster's angle, it can have a better light incident ratio. The relative relationship between the wavelength of the light L, the material of the light conversion layer 110 and its refractive index, and the included angle θ will be recorded in Table 1 below.

Table 1

Next please refer to FIG. 2B. The photoelectric conversion element 100a in FIG. 2B is similar to the photoelectric conversion element 100 in FIG. . In this embodiment, the material of the passivation layer 160 is, for example, silicon nitride or silicon oxide. When the light incident side 110 c is covered with the protective layer 160 , and the light L enters the light conversion layer 110 through the protective layer 160 , the included angle θ is preferably between 64° and 69°. The wavelength of light L, the material (silicon nitride) and its refractive index of the protective layer 170 , the material of the light conversion layer 110 and its refractive index, and the relative relationship between the included angle θ will be recorded in Table 2 below.

Table 2

Next please refer to FIG. 3A, the photoelectric conversion element 100b in FIG. 3A is similar to the photoelectric conversion element 100 in FIG. Between the type-doped semiconductor layer 150 and the bottom conductive layer 120 . When the reflective layer 170 is disposed on the bottom conductive layer 120 , the material selection of the bottom conductive layer 120 will be more flexible. In detail, the bottom conductive layer 120 can be made of a transparent conductive material or a reflective conductive material.

Next please refer to FIG. 3B. The photoelectric conversion element 100c in FIG. 3B is similar to the photoelectric conversion element 100b in FIG. .

Finally, please refer to FIG. 4A, FIG. 4B, FIG. 5A and FIG. 5B. It can be seen from FIG. 4A, FIG. 4B, FIG. 5A and FIG. 100c is similar, but the main difference is that: the top conductive layer 130 in the photoelectric conversion elements 100d, 100e, 100f, 100g has a rough surface 130a, and the rough surface 130a is not in contact with the top plane 110b of the light conversion layer 110. In a variant embodiment, the protection layer can also cover the top conductive layer 130, and a rough surface is made on the surface to reduce light reflection.

Since the light conversion layer in the photoelectric conversion element of the present invention has an inclined light incident side, the incident angle of light incident on the light conversion layer satisfies the condition of Brewster's angle, so the photoelectric conversion element of the present invention has good sensitivity and photoelectricity. conversion efficiency.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention.

Claims (16)

1. A photoelectric conversion element, characterized in that, is suitable for converting a light into a photocurrent, and the photoelectric conversion element comprises: A light conversion layer has a bottom plane, a top plane relative to the bottom plane, and a light incident side connected between the bottom plane and the top plane, wherein the angle between the bottom plane and the light incident side is θ, and 64°≤θ≤79°; a top conductive layer disposed on the top plane of the light conversion layer; and A bottom conductive layer is arranged under the bottom plane of the light conversion layer. 2 . The photoelectric conversion element according to claim 1 , wherein the incident angle of the light incident on the light incident side surface is θ _i , and θ is equal to θ _i . 3. The photoelectric conversion element according to claim 1, wherein the photo conversion layer comprises an intrinsic semiconductor layer. 4. The photoelectric conversion element according to claim 1, wherein the light conversion layer comprises an amorphous silicon layer, a microcrystalline silicon layer, a polysilicon layer, an epitaxial silicon layer, a silicon-rich material layer, a A silicon germanium layer, a gallium arsenic layer or a stack thereof. 5. The photoelectric conversion element according to claim 1, further comprising: a first type doped semiconductor layer disposed between the bottom conductive layer and the light conversion layer; and A second-type doped semiconductor layer is disposed between the top conductive layer and the light conversion layer. 6 . The photoelectric conversion element according to claim 5 , wherein the first-type doped semiconductor layer is an N-type doped semiconductor layer, and the second-type doped semiconductor layer is a P-type doped semiconductor layer. 7 . The photoelectric conversion element according to claim 5 , wherein the first-type doped semiconductor layer is a P-type doped semiconductor layer, and the second-type doped semiconductor layer is an N-type doped semiconductor layer. 8. The photoelectric conversion device according to claim 5, further comprising a reflective layer disposed between the first type doped semiconductor layer and the bottom conductive layer. 9. The photoelectric conversion device according to claim 1, further comprising a reflective layer disposed between the first-type doped semiconductor layer and the bottom conductive layer. 10 . The photoelectric conversion device according to claim 1 , wherein the top conductive layer has a rough surface, and the rough surface is not in contact with the top plane of the light conversion layer. 11 . 11. The photoelectric conversion element according to claim 1, wherein 75°≤θ≤79°. 12. The photoelectric conversion element according to claim 1, further comprising a protective layer covering the light incident side. 13 . The photoelectric conversion element according to claim 12 , wherein the protective layer is made of silicon nitride or silicon oxide. 14 . 14. The photoelectric conversion element according to claim 12, wherein 64°≤θ≤69°. 15. The photoelectric conversion element according to claim 1, wherein the shape of the bottom plane and the top plane is polygonal, circular or elliptical. 16. The photoelectric conversion device according to claim 1, wherein the top conductive layer is a transparent conductive layer, and the bottom conductive layer is a reflective conductive layer.

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