TWI445192B - Thin film solar cell and manufacturing method thereof - Google Patents

Description

Thin film type solar cell and manufacturing method thereof

The present invention relates to a thin film type solar cell having a small dark current, a large open circuit voltage, and including a hetero semiconductor layer, and a method of fabricating the same.

A solar cell is a photovoltaic element that utilizes the photoelectric effect to convert the light energy released by the sun into electrical energy. Thin film solar cells have become one of the focuses of solar cell development due to their low cost. The thin film type solar cell is, for example, Amorphous Si, Micro Si, CdTe, Copper Indium Selenide (CIS), and Copper Indium Gallium Selenide (CIGS).

The structure of a thin film type solar cell generally includes a substrate, a lower conductive layer, an upper conductive layer, a P-type semiconductor layer, an intrinsic semiconductor layer, an N-type semiconductor layer, and an electrode layer. However, the aforementioned thin film type solar cell has a large dark current and a small open circuit voltage, and the above is still a technical problem to be solved.

In view of various problems of the prior art, the inventors have proposed a thin film type solar cell based on years of research and development and many practical experiences, as an implementation method and basis for improving the above disadvantages.

It is an object of the present invention to provide a thin film type solar cell having a small dark current.

Another object of the present invention is to provide a thin film type solar cell having a large open circuit voltage.

It is still another object of the present invention to provide a thin film type solar cell including a hetero semiconductor layer.

According to the above object of the present invention, the present invention provides a thin film solar cell comprising at least: a substrate, a first conductive layer, a second conductive layer, and a first semiconductor layer, wherein the first semiconductor layer is selectively a P-type semiconductor layer or an N-type semiconductor layer, a second semiconductor layer, and a third semiconductor layer, an electrode layer, and a hetero-semiconductor layer, the material of the hetero-semiconductor layer being selectively selected from the first semiconductor layer or the third semiconductor The material of the layer is different, and the hetero semiconductor layer is selectively a P-type hetero semiconductor layer, an N-type hetero semiconductor layer or an intrinsic semiconductor layer; the substrate, the first conductive layer, the first semiconductor layer, and the hetero semiconductor layer The second semiconductor layer, the third semiconductor layer, the second conductive layer, and the electrode layer are sequentially stacked; or the substrate, the first conductive layer, the first semiconductor layer, the second semiconductor layer, The hetero semiconductor layer, the third semiconductor layer, the second conductive layer and the electrode layer are sequentially stacked; the structure of the thin film solar cell of the present invention comprises a hetero semiconductor layer, the heterogeneous half The conductor layer forms a heterojunction, and the materials on both sides of the heterojunction are different from each other, for example, a microcrystalline semiconductor on one side and an amorphous germanium on the other side, so that the dark current is small and the open circuit voltage is large. .

The invention further provides a double junction type thin film solar cell, comprising at least: a substrate, a first conductive layer, a first solar cell, a junction layer, and a second solar cell. The substrate, the first conductive layer, the first solar cell, the junction layer and the second solar cell are sequentially stacked, the second solar cell comprises at least one heterogeneous semiconductor layer; and the structure of the double junction thin film solar cell of the invention Heterogeneous semiconductor layer The heterogeneous semiconductor layer forms a heterojunction, and the materials on both sides of the heterojunction are different from each other, for example, a microcrystalline germanium on one side and an amorphous germanium on the other side, thus having a small dark current and an open circuit voltage Great advantage.

The invention further provides a three-junction type thin film solar cell, comprising at least: a substrate, a first conductive layer, a first solar cell, a first junction layer, a second solar cell, and a second junction Layer, a third solar cell. The substrate, the first conductive layer, the first solar cell, the first junction layer, the second solar cell, the second junction layer, and the third solar cell are sequentially stacked, and the second solar cell or the third solar cell includes at least At least one hetero semiconductor layer; the structure of the triple junction thin film solar cell of the present invention comprises a hetero semiconductor layer, the hetero semiconductor layer forming a heterojunction, the materials on both sides of the heterojunction being different from each other, for example, one side It is a microcrystalline germanium semiconductor and the other side is an amorphous germanium semiconductor, so it has the advantages of a small dark current and a large open circuit voltage.

The present invention provides a method for fabricating a thin film solar cell, comprising at least the steps of: providing a substrate; forming a first conductive layer on the substrate; and forming a first semiconductor layer on the first conductive layer, the first a semiconductor layer is a P-type semiconductor layer or an N-type semiconductor layer; a hetero semiconductor layer is formed on the first semiconductor layer, and the hetero semiconductor layer is a P-type hetero semiconductor layer or an N-type hetero semiconductor layer, and the first semiconductor layer is The material is different from the material of the hetero semiconductor layer. When the first semiconductor layer is a P-type semiconductor layer, the hetero semiconductor layer is a P-type hetero semiconductor layer, and when the first semiconductor layer is an N-type semiconductor layer, the heterogeneity The semiconductor layer is an N-type hetero semiconductor layer; a second semiconductor layer is formed on the hetero semiconductor layer; and a third semiconductor layer is formed on the second semiconductor layer, the third semiconductor layer is a P-type semiconductor layer or an N-type semiconductor a layer, when the first semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is N-type a semiconductor layer, wherein the third semiconductor layer is a P-type semiconductor layer; a second conductive layer is formed on the third semiconductor layer; and the second conductive layer is formed on the second conductive layer An electrode layer.

The invention further provides a method for fabricating a thin film solar cell, comprising at least the steps of: providing a substrate; forming a first conductive layer on the substrate, the first semiconductor layer being a P-type semiconductor layer or an N-type semiconductor layer Forming a first semiconductor layer on the first conductive layer; forming a second semiconductor layer on the first semiconductor layer; forming a hetero semiconductor layer on the second semiconductor layer, the material of the hetero semiconductor layer and the The material of the second semiconductor layer is different, and the hetero semiconductor layer is a P-type hetero semiconductor layer or an N-type hetero semiconductor layer. When the third semiconductor layer is a P-type semiconductor layer, the hetero semiconductor layer is a P-type hetero semiconductor layer. When the third semiconductor layer is an N-type semiconductor layer, the hetero semiconductor layer is an N-type hetero semiconductor layer; and a third semiconductor layer is formed on the hetero semiconductor layer, the third semiconductor layer is a P-type semiconductor layer or an N-type a semiconductor layer, when the first semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and when the first semiconductor layer is an N-type semiconductor layer, the third semiconductor layer is a P-type semiconductor layer; a second conductive layer formed on the third semiconductor layer; and an electrode layer formed on the second conductive layer.

For a better understanding and understanding of the technical features and the efficacies of the present invention, the preferred embodiments and the detailed description are as follows.

11‧‧‧Substrate

12‧‧‧First conductive layer

13‧‧‧Second conductive layer

14‧‧‧First semiconductor layer

15‧‧‧Second semiconductor layer

16‧‧‧ Third semiconductor layer

17‧‧‧Electrical layer

18‧‧‧ Heterogeneous semiconductor layer

2‧‧‧Double junction thin film solar cells

21‧‧‧Substrate

22‧‧‧First conductive layer

23‧‧‧First solar cell

24‧‧‧Contact layer

25‧‧‧Second solar cell

3‧‧‧Three junction thin film solar cells

31‧‧‧Substrate

32‧‧‧First conductive layer

33‧‧‧First solar cell

34‧‧‧Connecting layer

35‧‧‧Second solar cell

36‧‧‧Connection layer

37‧‧‧ Third solar cell

100‧‧‧ steps

200‧‧‧ steps

300‧‧‧Steps

400‧‧‧ steps

500‧‧‧ steps

600‧‧‧ steps

700‧‧‧ steps

800‧‧‧ steps

101‧‧‧Steps

201‧‧‧Steps

301‧‧‧Steps

401‧‧‧ steps

501‧‧‧Steps

601‧‧ steps

701‧‧‧Steps

102‧‧‧Steps

202‧‧‧Steps

302‧‧‧Steps

402‧‧‧Steps

502‧‧‧Steps

602‧‧ steps

702‧‧‧Steps

802‧‧ steps

1 is a schematic view of a first preferred embodiment of a thin film solar cell of the present invention; and FIG. 2 is a schematic flow chart of a method for fabricating a first preferred embodiment of the thin film solar cell of the present invention; A schematic view of a second preferred embodiment of the inventive thin film solar cell; 4 is a schematic flow chart of a method for fabricating a second preferred embodiment of the thin film solar cell of the present invention; FIG. 5 is a schematic view showing a third preferred embodiment of the thin film solar cell of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 7 is a schematic view showing a fourth preferred embodiment of a thin film solar cell of the present invention; and FIG. 8 is a view of a thin film solar cell of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 5 is a schematic view showing the dark current of a thin film solar cell of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the preferred embodiments of the thin film solar cell of the present invention will be described with reference to the accompanying drawings.

First, please refer to FIG. 1, which is a schematic view showing a first preferred embodiment of the thin film solar cell of the present invention. The thin film solar cell of the present invention comprises at least a substrate 11, a first conductive layer 12, a second conductive layer 13, a first semiconductor layer 14, a second semiconductor layer 15, a third semiconductor layer 16, an electrode layer 17, and a hetero semiconductor layer 18. The substrate 11 is, for example, glass, and the foregoing is by way of example only and not limitation. The first conductive layer 12 or the second conductive layer 13 is, for example, a Transparent Conductive Oxide Layer (TCO), and the foregoing is by way of example only and not limitation. The first semiconductor layer 14 is selectively a P-type semiconductor layer or an N-type semiconductor layer. The third semiconductor layer 16 is also selectively a P-type semiconductor layer or an N-type semiconductor layer. When the first semiconductor layer 14 is a P-type semiconductor layer, the third semiconductor layer 16 is an N-type semiconductor layer; and when the first semiconductor layer 14 is an N-type semiconductor layer, the third semiconductor layer 16 is a P-type semiconductor layer . The electrode layer 17 is, for example, silver The electrode layer, the foregoing is by way of example only and not limitation.

The material of the hetero semiconductor layer 18 is different from the material of the first semiconductor layer 14. For example, the material of the hetero semiconductor layer 18 is an amorphous germanium semiconductor, and the material of the first semiconductor layer 14 is a microcrystalline germanium semiconductor, and the foregoing is by way of example only and not limitation. The hetero semiconductor layer 18 is selectively a P-type hetero semiconductor layer or an N-type hetero semiconductor layer. When the first semiconductor layer 14 is a P-type semiconductor layer, the hetero semiconductor layer 18 is a P-type hetero semiconductor layer; when the first semiconductor layer 14 is an N-type semiconductor layer, the hetero semiconductor layer 18 is an N-type hetero semiconductor layer. The hetero semiconductor layer 18 forms a heterojunction, and the materials on both sides of the heterojunction are different from each other.

The substrate 11, the first conductive layer 12, the first semiconductor layer 14, the hetero semiconductor layer 18, the second semiconductor layer 15, the third semiconductor layer 16, the second conductive layer 13, and the electrode layer 17 are sequentially stacked.

Please refer to FIG. 2, which is a schematic flow chart showing the manufacturing method of the first preferred embodiment of the thin film solar cell of the present invention. The manufacturing method of the first preferred embodiment of the thin film solar cell of the present invention comprises at least the following steps:

Step 100: Perform a preparation step of providing a substrate, such as glass.

Step 200: performing a first fabrication step of fabricating a first conductive layer on the substrate.

Step 300: Perform a second fabrication step of fabricating a first semiconductor layer on the first conductive layer.

Step 400: Perform a third fabrication step of fabricating a hetero semiconductor layer on the first semiconductor layer.

Step 500: Perform a fourth fabrication step to form a second half on the hetero semiconductor layer Conductor layer.

Step 600: Perform a fifth fabrication step of fabricating a third semiconductor layer on the second semiconductor layer.

Step 700: Perform a sixth fabrication step of fabricating a second conductive layer on the third semiconductor layer.

Step 800: Perform a seventh fabrication step of forming an electrode layer on the second conductive layer.

Thus, the fabrication of the first preferred embodiment of the thin film solar cell of the present invention is completed.

Please refer to FIG. 3, which is a schematic view showing a second preferred embodiment of the thin film solar cell of the present invention. The thin film solar cell of the present invention comprises at least a substrate 11, a first conductive layer 12, a second conductive layer 13, a first semiconductor layer 14, a second semiconductor layer 15, a third semiconductor layer 16, an electrode layer 17, and a hetero semiconductor layer 18. The substrate 11 is, for example, glass, and the foregoing is by way of example only and not limitation. The first conductive layer 12 or the second conductive layer 13 is, for example, a transparent conductive layer, and the foregoing is by way of example only and not limitation. The first semiconductor layer 14 is selectively a P-type semiconductor layer or an N-type semiconductor layer. The third semiconductor layer 16 is also selectively a P-type semiconductor layer or an N-type semiconductor layer. When the first semiconductor layer 14 is a P-type semiconductor layer, the third semiconductor layer 16 is an N-type semiconductor layer; and when the first semiconductor layer 14 is an N-type semiconductor layer, the third semiconductor layer 16 is a P-type semiconductor layer . The electrode layer 17 is, for example, a silver electrode layer, and the foregoing is by way of example only and not limitation.

The difference from the foregoing first preferred embodiment is that the material of the hetero semiconductor layer 18 is different from the material of the second semiconductor layer 15. For example, the material of the hetero semiconductor layer 18 is an amorphous germanium semiconductor, and the material of the second semiconductor layer 15 is a microcrystalline germanium semiconductor. The foregoing is by way of example only and not limitation. The hetero semiconductor layer 18 is located between the second semiconductor layer 15 and the third semiconductor layer 16. The hetero semiconductor layer 18 is selectively a P-type hetero semiconductor layer or N Type heterogeneous semiconductor layer. When the third semiconductor layer 16 is a P-type semiconductor layer, the hetero semiconductor layer 18 is a P-type hetero semiconductor layer; when the third semiconductor layer 16 is an N-type semiconductor layer, the hetero semiconductor layer 18 is an N-type hetero semiconductor layer. The hetero semiconductor layer 18 forms a heterojunction, and the materials on both sides of the heterojunction are different from each other.

The substrate 11, the first conductive layer 12, the first semiconductor layer 14, the second semiconductor layer 15, the hetero semiconductor layer 18, the third semiconductor layer 16, the second conductive layer 13, and the electrode layer 17 are sequentially stacked.

Please refer to FIG. 4, which is a schematic flow chart showing a manufacturing method of a second preferred embodiment of the thin film solar cell of the present invention. The manufacturing method of the second preferred embodiment of the thin film solar cell of the present invention comprises at least the following steps:

Step 101: Perform a preparation step of providing a substrate, such as glass.

Step 201: Perform a first fabrication step of fabricating a first conductive layer on the substrate.

Step 301: Perform a second fabrication step of fabricating a first semiconductor layer on the first conductive layer.

Step 401: Perform a third fabrication step of fabricating a second semiconductor layer on the first semiconductor layer.

Step 501: Perform a fourth fabrication step of fabricating a hetero semiconductor layer on the second semiconductor layer.

Step 601: Perform a fifth fabrication step of fabricating a third semiconductor layer on the hetero semiconductor layer.

Step 701: Perform a sixth fabrication step of fabricating a second conductive layer on the third semiconductor layer.

Step 801: Perform a seventh fabrication step of forming an electrode layer on the second conductive layer.

Thus, the fabrication of the second preferred embodiment of the thin film solar cell of the present invention is completed.

Referring to Figure 5, there is shown a schematic view of a third preferred embodiment of the thin film solar cell of the present invention. The thin film solar cell of the present invention comprises at least a substrate 11, a first conductive layer 12, a second conductive layer 13, a first semiconductor layer 14, a second semiconductor layer 15, a third semiconductor layer 16, an electrode layer 17, and a hetero semiconductor layer 18. The substrate 11 is, for example, glass, and the foregoing is by way of example only and not limitation. The first conductive layer 12 or the second conductive layer 13 is, for example, a transparent conductive layer, and the foregoing is by way of example only and not limitation. The first semiconductor layer 14 is selectively a P-type semiconductor layer or an N-type semiconductor layer. The third semiconductor layer 16 is also selectively a P-type semiconductor layer or an N-type semiconductor layer. When the first semiconductor layer 14 is a P-type semiconductor layer, the third semiconductor layer 16 is an N-type semiconductor layer; when the first semiconductor layer 14 is an N-type semiconductor layer, the third semiconductor layer 16 is a P-type semiconductor layer. The electrode layer 17 is, for example, a silver electrode layer, and the foregoing is by way of example only and not limitation.

The hetero semiconductor layer 18 is located between the second semiconductor layer 15 and the third semiconductor layer 16. The material of the hetero semiconductor layer 18 is different from the material of the second semiconductor layer 15. For example, the material of the hetero semiconductor layer 18 is an amorphous germanium semiconductor, and the material of the second semiconductor layer 15 is a microcrystalline germanium semiconductor. The foregoing is by way of example only and not limitation. The difference from the foregoing second preferred embodiment is that the hetero semiconductor layer 18 is an intrinsic semiconductor layer. The hetero semiconductor layer 18 forms a heterojunction, and the materials on both sides of the heterojunction are different from each other.

Please refer to FIG. 6 , which is a schematic flow chart showing a manufacturing method of a third preferred embodiment of the thin film solar cell of the present invention. The manufacturing method of the third preferred embodiment of the thin film solar cell of the present invention comprises at least the following steps:

Step 102: Perform a preparation step of providing a substrate, such as glass.

Step 202: Perform a first fabrication step of fabricating a first conductive layer on the substrate.

Step 302: Perform a second fabrication step of fabricating a first semiconductor layer on the first conductive layer.

Step 402: Perform a third fabrication step of fabricating a second semiconductor layer on the first semiconductor layer.

Step 502: Perform a fourth fabrication step of fabricating a hetero semiconductor layer on the second semiconductor layer.

Step 602: Perform a fifth fabrication step of fabricating a third semiconductor layer on the hetero semiconductor layer.

Step 702: Perform a sixth fabrication step of fabricating a second conductive layer on the third semiconductor layer.

Step 802: Perform a seventh fabrication step of fabricating an electrode layer on the second conductive layer.

Thus, the fabrication of the third preferred embodiment of the thin film solar cell of the present invention is completed.

Referring to Figure 7, there is shown a schematic view of a fourth preferred embodiment of the thin film solar cell of the present invention. The first preferred embodiment, the second preferred embodiment or the third preferred embodiment of the thin film solar cell of the present invention is more applicable to the double junction type thin film solar cell 2. As shown in FIG. 7, the double junction type thin film solar cell includes at least a substrate 21, a first conductive layer 22, a first solar cell 23, a junction layer 24, and a second solar cell 25. The substrate 21, the first conductive layer 22, the first solar cell 23, the junction layer 24, and the second solar cell 25 are sequentially stacked. The second solar cell 25 is selectively one of the first preferred embodiment, the second preferred embodiment or the third preferred embodiment of the thin film solar cell of the present invention. Specifically, the foregoing second solar cell 25 is required. Optionally, the substrate 11, the first conductive layer 12, the second conductive layer 13, or the electrode layer 17 are included, which will be readily understood by those skilled in the art, and will not be further described herein. The structure of the double junction type thin film solar cell 2 of the present invention comprises a hetero semiconductor layer, and the hetero semiconductor layer forms a heterojunction, and the materials on both sides of the heterojunction are different from each other, for example, a microcrystalline semiconductor on one side The other side is an amorphous germanium semiconductor.

Referring to Fig. 8, there is shown a schematic view of a fifth preferred embodiment of the thin film solar cell of the present invention. The first preferred embodiment, the second preferred embodiment or the third preferred embodiment of the thin film solar cell of the present invention is more applicable to the triple junction type thin film solar cell 3. As shown in FIG. 8, the triple junction type thin film solar cell 3 includes at least a substrate 31, a first conductive layer 32, a first solar cell 33, a first junction layer 34, a second solar cell 35, and a second junction. Layer 36, third solar cell 37. The substrate 31, the first conductive layer 32, the first solar cell 33, the first junction layer 34, the second solar cell 35, the second junction layer 36, and the third solar cell 37 are sequentially stacked. The second solar cell 35 is selectively one of the first preferred embodiment, the second preferred embodiment or the third preferred embodiment of the thin film solar cell of the present invention. The third solar cell 37 is also selectively one of the first preferred embodiment, the second preferred embodiment or the third preferred embodiment of the thin film solar cell of the present invention. It should be noted that the foregoing second solar cell 35 and third solar cell 37 selectively include or exclude the substrate 11, the first conductive layer 12, the second conductive layer 13 or the electrode layer 17, which is well known in the art. The technicians can easily understand and will not repeat them here. The structure of the three junction type thin film solar cell 3 of the present invention comprises a hetero semiconductor layer, and the hetero semiconductor layer forms a heterojunction, and the materials on both sides of the heterojunction are different from each other, for example, a microcrystalline semiconductor on one side The other side is an amorphous germanium semiconductor.

In summary, the thin film solar cell of the present invention has at least the following advantages:

The structure of the thin film type solar cell of the present invention includes a hetero semiconductor layer which forms a heterojunction, and the materials on both sides of the heterojunction are different from each other, so that the dark current is small and the open circuit voltage is large.

The above advantages can also be known from the following actual measurement data:

As can be seen from the above table, the open circuit voltage (Voc) of the thin film type solar cell not including the hetero semiconductor layer structure is 469 mV and the current density (Jsc) is 19.02 mA/cm 2 ; and the open circuit voltage of the thin film type solar cell including the hetero semiconductor layer structure (Voc) was 478 mV and current density (Jsc) was 19.23 mA/cm2.

Referring to FIG. 9, it is a schematic diagram showing the dark current of the thin film solar cell of the present invention. The figure shows a dark current (Hetero) of a thin film type solar cell including a hetero semiconductor layer structure and a dark current (Homo) of a thin film type solar cell not including a hetero semiconductor layer structure.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

11‧‧‧Substrate

12‧‧‧First conductive layer

13‧‧‧Second conductive layer

14‧‧‧First semiconductor layer

15‧‧‧Second semiconductor layer

16‧‧‧ Third semiconductor layer

17‧‧‧Electrical layer

18‧‧‧ Heterogeneous semiconductor layer

Claims (10)

A thin film solar cell comprising at least: a substrate; a first conductive layer; a second conductive layer; a first semiconductor layer, the first semiconductor layer being a P-type semiconductor layer or an N-type semiconductor layer; and a second semiconductor a third semiconductor layer, wherein when the first semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and when the first semiconductor layer is an N-type semiconductor layer, the first The three semiconductor layers are a P-type semiconductor layer; an electrode layer; and at least one hetero semiconductor layer, the material of the hetero semiconductor layer being different from the material of the first semiconductor layer, the hetero semiconductor layer being a P-type hetero semiconductor layer or N a heterogeneous semiconductor layer, wherein the hetero semiconductor layer is a P-type hetero semiconductor layer when the first semiconductor layer is a P-type semiconductor layer; and the N-type heterogeneous layer is an N-type heterogeneous layer when the first semiconductor layer is an N-type semiconductor layer a semiconductor layer; wherein the substrate, the first conductive layer, the first semiconductor layer, the hetero semiconductor layer, the second semiconductor layer, the third semiconductor layer, the second conductive layer, and the electrode layer Stacked up sequence, and the at least one layer of the hetero semiconductor material is amorphous silicon semiconductor. The thin film solar cell of claim 1, wherein the substrate is glass The first conductive layer or the second conductive layer is a transparent conductive layer, the electrode layer is a silver electrode layer, and the material of the first semiconductor layer is a microcrystalline semiconductor. A method for fabricating a thin film solar cell, comprising the steps of: providing a substrate; forming a first conductive layer on the substrate; and forming a first semiconductor layer on the first conductive layer, the first semiconductor layer being a P-type hetero semiconductor layer or an N-type hetero semiconductor layer; a hetero semiconductor layer is formed on the first semiconductor layer, the material of the hetero semiconductor layer is different from the material of the first semiconductor layer, and the hetero semiconductor layer is a P-type semiconductor a layer or an N-type semiconductor layer, when the hetero semiconductor layer is a P-type hetero semiconductor layer, the first semiconductor layer is a P-type semiconductor layer, and when the hetero semiconductor layer is an N-type hetero semiconductor layer, the first semiconductor layer is An N-type semiconductor layer; a second semiconductor layer is formed on the hetero-semiconductor layer; a third semiconductor layer is formed on the second semiconductor layer, and the third semiconductor layer is a P-type semiconductor layer or an N-type semiconductor layer. When the first semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and when the first semiconductor layer is an N-type semiconductor layer, the third semiconductor layer is a P-type semiconductor Layer; a second conductive layer is produced on the third semiconductor layer; and an electrode layer prepared on the second conductive layer. A thin film solar cell comprising at least: a substrate; a first conductive layer; a second conductive layer; a first semiconductor layer, the first semiconductor layer being a P-type semiconductor layer or an N-type semiconductor layer; a second semiconductor layer; wherein, when the first semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and when the first semiconductor layer is an N-type semiconductor layer The third semiconductor layer is a P-type semiconductor layer; an electrode layer; and at least one hetero-semiconductor layer, the material of the hetero-semiconductor layer being different from the material of the second semiconductor layer, the hetero-semiconductor layer being P-type heterogeneous a semiconductor layer or an N-type hetero semiconductor layer. When the third semiconductor layer is a P-type semiconductor layer, the hetero semiconductor layer is a P-type hetero semiconductor layer, and when the third semiconductor layer is an N-type semiconductor layer, the hetero semiconductor layer An N-type hetero semiconductor layer; wherein the substrate, the first conductive layer, the first semiconductor layer, the second semiconductor layer, the hetero semiconductor layer, the third semiconductor layer, the second conductive layer, and the electrode layer The materials are stacked in sequence, and the material of the at least one hetero semiconductor layer is an amorphous germanium semiconductor. The thin film solar cell of claim 4, wherein the substrate is glass, the first conductive layer or the second conductive layer is a transparent conductive layer, the electrode layer is a silver electrode layer, and the second semiconductor layer The material is a microcrystalline germanium semiconductor. A method for fabricating a thin film solar cell, comprising the steps of: providing a substrate; forming a first conductive layer on the substrate, the first semiconductor layer being a P-type semiconductor layer or an N-type semiconductor layer; a first semiconductor layer is formed on the conductive layer; a second semiconductor layer is formed on the first semiconductor layer; a hetero semiconductor layer is formed on the second semiconductor layer, and the material of the hetero semiconductor layer and the second semiconductor layer The material is different, and the hetero semiconductor layer is a P-type hetero semiconductor layer or an N-type hetero semiconductor layer, and when the third semiconductor layer is a P-type semiconductor layer The hetero semiconductor layer is a P-type hetero semiconductor layer. When the third semiconductor layer is an N-type semiconductor layer, the hetero semiconductor layer is an N-type hetero semiconductor layer; and a third semiconductor layer is formed on the hetero semiconductor layer. The third semiconductor layer is a P-type semiconductor layer or an N-type semiconductor layer. When the first semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, and when the first semiconductor layer is an N-type semiconductor layer The third semiconductor layer is a P-type semiconductor layer; a second conductive layer is formed on the third semiconductor layer; and an electrode layer is formed on the second conductive layer. A thin film solar cell comprising at least: a substrate; a first conductive layer; a second conductive layer; a first semiconductor layer, the first semiconductor layer being a P-type semiconductor layer or an N-type semiconductor layer; and a second semiconductor a third semiconductor layer, the third semiconductor layer is a P-type semiconductor layer or an N-type semiconductor layer, and when the first semiconductor layer is a P-type semiconductor layer, the third semiconductor layer is an N-type semiconductor layer, when When the first semiconductor layer is an N-type semiconductor layer, the third semiconductor layer is a P-type semiconductor layer; an electrode layer; and at least one hetero-semiconductor layer, the material of the hetero-semiconductor layer being different from the material of the second semiconductor layer, And the heterogeneous semiconductor layer is an intrinsic semiconductor layer; wherein the substrate, the first conductive layer, the first semiconductor layer, the second semiconductor layer, the hetero semiconductor layer, the third semiconductor layer, and the second conductive layer And the electrode layer is sequentially stacked, and the material of the at least one hetero semiconductor layer is an amorphous germanium semiconductor . The thin film solar cell of claim 7, wherein the substrate is glass, the first conductive layer or the second conductive layer is a transparent conductive layer, the electrode layer is a silver electrode layer, and the second semiconductor layer The material is a microcrystalline germanium semiconductor. A double junction type thin film solar cell comprises at least: a substrate; a first conductive layer; a first solar cell; a junction layer; a second solar cell; and the substrate, the first conductive layer, The first solar cell, the junction layer and the second solar cell are sequentially stacked. The second solar cell comprises at least one hetero semiconductor layer, and the material of the at least one hetero semiconductor layer is an amorphous germanium semiconductor. A three-junction type thin film solar cell comprising at least: a substrate; a first conductive layer; a first solar cell; a first junction layer; a second solar cell; a second junction layer; a solar cell; and the substrate, the first conductive layer, the first solar cell, the first junction layer, the second solar cell, the second junction layer, and the third solar cell are sequentially stacked The second solar cell or the third solar cell includes at least one hetero semiconductor layer, and the material of the at least one hetero semiconductor layer is an amorphous germanium semiconductor.