CN108447925B - Flexible heterojunction solar cell array based on horizontally arranged nanowire films and preparation method thereof - Google Patents

Abstract

The invention discloses a flexible heterojunction solar cell array based on horizontally arranged nanowire films and a preparation method thereof. It includes a flexible substrate layer, a solar cell array, and a flexible packaging layer. The solar cell array is disposed between the flexible substrate layer and the packaging layer and includes matrix-arranged solar cell structural units and copper connecting lines. The solar cell structural units Including p-type nanowire film, n-type semiconductor film, titanium electrode and double-layer gold electrode. First prepare the titanium electrode and the first layer of gold electrode; then transfer the p-type nanowire film to the appropriate position and prepare the second layer of gold electrode; then prepare the n-type semiconductor film and deposit the copper connection line; then spin-coat the flexible substrate layer and The device transfer is completed using sacrificial layer etching; finally, the flexible packaging layer is spin-coated. The invention gives full play to the advantages of nanodevices in the field of flexible solar cells and solves the problem of small effective area.

Description

Flexible heterojunction solar cell array based on horizontally arranged nanowire films and its Preparation

Technical areas:

The present invention relates to the field of flexible solar cells, and in particular to a flexible heterojunction solar cell based on horizontally arranged nanowire films and a preparation method thereof.

Background technique:

With the development of information society, the integration of people and information has become the future development trend of information technology, and flexible electronic devices are an important part of it. The concept of flexible electronics technology comes from organic electronics, but organic semiconductor materials cannot be widely used in modern electronic systems that emphasize high performance due to their own characteristics. Rogers and Huang from the University of Illinois proposed a flexible optoelectronic device based on a traditional inorganic semiconductor film. They divided the film into regions and connected each functional part through wires. Although this method achieved flexibility of the device, it reduced the effective area of the film, thus reducing the cost. device density. Nano-semiconductor materials have extremely high mechanical strength and can maintain their various properties in a bent state; a single nano-device can avoid structural damage caused by macroscopic deformation of the entire device due to its extremely small size. Therefore, nano-semiconductor materials and devices will become important building components of high-performance flexible solar cells. However, current various types of nano-flexible solar cells generally have the problem of small effective area. Therefore, how to increase the effective area through device integration has become the main problem facing the development of nano-flexible solar cells.

Contents of the invention:

In view of the shortcomings of the existing technology, the present invention proposes a flexible heterojunction solar cell array based on horizontally arranged nanowire films and a preparation method thereof, aiming to obtain nano-flexible solar cells with high device density and large effective area.

In order to achieve the above objectives, the present invention proposes a flexible heterojunction solar cell array based on horizontally arranged nanowire films, which is characterized by: including a flexible substrate (1), a solar cell array, and a flexible packaging layer (8), the solar cell array is arranged between the flexible substrate (1) and the flexible packaging layer (8), the solar cell array includes a matrix arrangement of solar cell structural units and copper connecting wires (7), the The number of solar cell structural units arranged in a matrix is greater than or equal to 2 in each row and column.

Preferably, it is characterized in that: the flexible substrate (1) and the flexible packaging layer (8) are PDMS, the thickness of the flexible substrate (1) is 1000-3000 μm, and the thickness of the flexible packaging layer (8) is 500 μm. -1000μm.

Preferably, it is characterized in that: the spacing between the solar cell structural units arranged in a matrix is 100 μm-1000 μm, the thickness of the copper connection line (7) is 50-200 nm, and the width is 5-20 μm. 7) Includes three types of copper connecting wires (7-1), copper connecting wires (7-2), and copper connecting wires (7-3).

Preferably, it is characterized in that: the solar cell structural unit is a heterojunction solar cell based on horizontally arranged nanowire films, including a first layer of gold electrode (2), and the first layer of gold electrode (2) is provided with There is a horizontally arranged p-type nanowire film (3). One side of the horizontally arranged p-type nanowire film (3) covers the first layer of gold electrode (2), and a second layer of gold is provided on this side. Electrode (4), an n-type semiconductor film (5) is provided under the other side of the horizontally arranged p-type nanowire film (3), and a titanium electrode is provided on one end of the n-type semiconductor film (5) (6). Preferably, it is characterized in that the solar cell array is composed of the copper connecting wires (7) in a specific connection mode between the solar cell structural units arranged in the matrix, and the specific connection mode is the upper part of each column. The n-type semiconductor film (5) of the solar cell structural unit is connected to the titanium electrode (6) of the lower solar cell structural unit through a copper connecting wire (7-1), and the first layer of gold electrode (6) of the upper solar cell structural unit in each column is 2) Connect the first layer of gold electrodes (2) of the lower solar cell structural units through copper connecting wires (7-2), and the left solar cell structural units in the top row of the solar cell structural units arranged in the array. The first-layer gold electrode (2) is connected to the titanium electrode (6) of the right solar cell structural unit through a copper connecting wire (7-3).

Preferably, the solar cell structural unit is characterized in that the first layer gold electrode (2) and the second layer gold electrode (4) completely overlap, and the first layer gold electrode (2) The thickness of the second layer of gold electrode (4) is 30-50nm, and the thickness of the second layer of gold electrode (4) is 50-100nm.

Preferably, the solar cell structural unit is characterized in that: the thickness of the horizontally arranged p-type nanowire film (3) is 200-1000 nm, and the p-type nanowires are p-type CdTe nanowires.

Preferably, the solar cell structural unit is characterized in that: the n-type semiconductor film (5) is an n-type ZnO film, the thickness of the n-type semiconductor film (5) is 150-500nm, and the n-type semiconductor film (5) is an n-type ZnO film. The distance between the thin film (5) and the first layer gold electrode (2) is 5-20 μm. In order to achieve the above objects, the preparation method of the present invention includes the following sequential steps:

1) Use the magnetron sputtering method to prepare a titanium electrode array and a gold electrode array with a thickness of 30-50nm on a silicon substrate covered with a silicon dioxide layer;

2) Apply photoresist on the surface of the substrate, and carve a rectangular window array on the surface of the substrate through UV exposure and development. The inside of the rectangular window is not covered by photoresist and the silicon dioxide layer is exposed, and the outside of the rectangular window is covered by photoresist. The interior of the rectangular window contains gold electrodes and no titanium electrodes;

3) Transfer the p-type nanowires to the window area described in step 2) to form a horizontally arranged p-type nanowire film, and cover one side of the p-type nanowire film with a gold electrode;

4) Repeat step 3) two or more times to make the formed horizontally arranged p-type nanowire film reach 200-1000nm;

5) Remove the photoresist outside the rectangular window;

6) Use the magnetron sputtering method to prepare a gold electrode with the same shape and size as the gold electrode described in step 1) and a thickness of 50-100nm at the same position of the gold electrode described in step 1), so that the p-type nanometer One side of the line film forms a sandwich structure with two layers of gold electrodes;

7) Use pulse laser deposition method to prepare an n-type semiconductor film with a thickness of 150-500 nm, so that the prepared n-type semiconductor film covers part of the p-type nanowire film and covers part of the titanium electrode. The prepared n-type semiconductor film and its right side The distance between gold electrodes is 5-20μm;

8) Use magnetron sputtering to prepare copper connecting lines with a thickness of 50-200nm and a width of 5-20μm;

9) Use the spin coating method to spin-coat a flexible substrate layer with a thickness of 1000-3000 μm on the substrate surface to cover the entire solar cell array and copper connecting lines;

10) Use sacrificial layer etching to peel off the flexible substrate layer and solar cell array from the silicon substrate covered with the silicon dioxide layer;

11) Use the spin coating method to spin-coat a flexible encapsulation layer with a thickness of 500-1000 μm on the flexible substrate layer, so that the entire solar cell array is covered between the flexible substrate layer and the flexible encapsulation layer.

Compared with the prior art, the present invention has the following beneficial results:

1. In the present invention, a heterojunction solar cell is constructed by combining a horizontally arranged p-type nanowire film and an n-type semiconductor film, which avoids the strict requirements of nanometer vertical array structure solar cells on device substrates and difficulty in achieving flexibility. Application problems;

2. In the present invention, copper connecting wires are used to arrange solar cell structural units composed of heterojunctions based on horizontally arranged nanowire films in a matrix arrangement to form a solar cell array, which effectively solves the current problem of small effective area of nanosolar cells. .

Picture description:

Figure 1A is a schematic cross-sectional structural view of the present invention, and Figure 1B is a schematic top view of the present invention.

Figure 2 is a production process flow chart (schematic cross-sectional structural diagram) of the present invention

Figure 3 is a manufacturing process flow chart (schematic top view) of the present invention.

Detailed ways:

Referring to Figures 1A and 1B, the present invention includes a flexible substrate (1), a solar cell array, and a flexible packaging layer (8). The solar cell array is provided on the flexible substrate (1) and the flexible packaging layer (8). 8), the solar cell array includes solar cell structural units arranged in a matrix and copper connecting wires (7), and the number of solar cell structural units arranged in a matrix is greater than or equal to 2 in each row and column.

The flexible substrate (1) is PDMS with a thickness of 1000-3000 μm; the flexible packaging layer (8) is PDMS with a thickness of 500-1000 μm; the spacing between the solar cell structural units arranged in the matrix is 100 μm-1000 μm; The thickness of the copper connection line (7) is 50-200nm and the width is 5-20μm; the copper connection line (7) includes a copper connection line (7-1), a copper connection line (7-2), a copper connection line There are three types of lines (7-3). The solar cell structural unit is a heterojunction solar cell based on a horizontally arranged nanowire film, including a first layer of gold electrode (2), and the first layer of gold electrode (2) is provided with a horizontally arranged p-type nanometer Line film (3), one side of the horizontally arranged p-type nanowire film (3) covers the first layer of gold electrode (2), and a second layer of gold electrode (4) is provided on this side, the An n-type semiconductor film (5) is provided under the other side of the horizontally arranged p-type nanowire film (3), and a titanium electrode (6) is provided on one end of the n-type semiconductor film (5).

The solar cell array is composed of the copper connecting wires (7) between the solar cell structural units arranged in the matrix according to a specific connection method. The specific connection method is an n-type solar cell structural unit in the upper part of each column. The semiconductor film (5) is connected to the titanium electrode (6) of the lower solar cell structural unit through a copper connecting wire (7-1), and the first layer gold electrode (2) of the upper solar cell structural unit in each column is connected through a copper connecting wire (7-1). 7-2) Connect the first-layer gold electrode (2) of the lower solar cell structural unit to the first-layer gold electrode (2) of the left solar cell structural unit in the top row of the solar cell structural units arranged in the array. ) Connect the titanium electrode (6) of the right solar cell structural unit through a copper connecting wire (7-3).

The positions of the first layer gold electrode (2) and the second layer gold electrode (4) completely overlap, the thickness of the first layer gold electrode (2) is 30-50nm, and the second layer gold electrode (4) 4) The thickness is 50-100nm; the thickness of the horizontally arranged p-type nanowire film (3) is 200-1000nm, the p-type nanowire is a p-type CdTe nanowire; the n-type semiconductor film (5) is n-type ZnO film, the n-type semiconductor film

(5) The thickness is 150-500 nm, and the distance between the n-type semiconductor film (5) and the first layer gold electrode (2) is 5-20 μm.

Referring to Figures 2 and 3, three examples of manufacturing flexible heterojunction solar cells based on horizontally arranged nanowire films are given below:

Example 1:

The number of solar cell structural units arranged in a matrix is 3 per row and 2 per column, the thickness of the flexible substrate is 1000 μm, the thickness of the flexible packaging layer is 500 μm, and the spacing between the solar cell structural units arranged in the matrix is 300 μm, as described The thickness of the copper connecting wire is 100nm and the width is 10μm. The thickness of the first layer of gold electrode in the solar cell structural unit is 30nm. The thickness of the second layer of gold electrode is 50nm. The thickness of the horizontally arranged p-type nanowire film is 400nm. The thickness of the n-type semiconductor film is 200 nm, and the distance between the n-type semiconductor film and the first layer of gold electrode is 10 μm. The production steps are as follows:

1) Use the magnetron sputtering method to prepare a titanium electrode array with 2 rows and 3 columns and a gold electrode array with a thickness of 30nm on a silicon substrate covered with a silicon dioxide layer, as shown in Figure 2-A and Figure 3- A;

2) Apply photoresist on the surface of the substrate, and carve a rectangular window array on the surface of the substrate through UV exposure and development. The inside of the rectangular window is not covered by photoresist and the silicon dioxide layer is exposed, and the outside of the rectangular window is covered by photoresist. The inside of the rectangular window contains gold electrodes and does not contain titanium electrodes, as shown in Figure 2-B and Figure 3-B;

3) Transfer the p-type nanowires to the window area described in step 2) to form a horizontally arranged p-type nanowire film, and cover one side of the p-type nanowire film with a gold electrode, as shown in Figure 2- C and Figure 3-C;

4) Repeat step 3) twice to make the formed horizontally arranged p-type nanowire film reach 400nm, as shown in Figure 2-C and Figure 3-C;

5) Remove the photoresist outside the rectangular window, as shown in Figure 2-D and Figure 3-D;

6) Use the magnetron sputtering method to prepare a gold electrode with the same shape and size as the gold electrode described in step 1) and a thickness of 50nm at the same position of the gold electrode described in step 1), so that a p-type nanowire film One side of the electrode forms a sandwich structure with two layers of gold electrodes, as shown in Figure 2-E and Figure 3-E;

7) Use pulse laser deposition method to prepare an n-type semiconductor film with a thickness of 200nm, so that the prepared n-type semiconductor film covers part of the p-type nanowire film and covers part of the titanium electrode, and the prepared n-type semiconductor film and the gold electrode on the right side The spacing is 10μm, as shown in Figure 2-F and Figure 3-F;

8) Use magnetron sputtering to prepare copper connecting lines with a thickness of 100nm and a width of 10μm, as shown in Figure 2-G and Figure 3-G;

9) Use the spin coating method to spin-coat a flexible substrate layer with a thickness of 1000 μm on the substrate surface so that it covers the entire solar cell array and copper connecting lines, as shown in Figure 2-H and Figure 3-H;

10) Use the sacrificial layer etching method to peel off the flexible substrate layer and solar cell array from the silicon substrate covered with the silicon dioxide layer, as shown in Figure 2-I and Figure 3-I;

11) Use the spin coating method to spin-coat a flexible packaging layer with a thickness of 500 μm on the flexible substrate layer, so that the entire solar cell array is covered between the flexible substrate layer and the flexible packaging layer, as shown in Figure 2-J and Figure 3-J.

Example 2:

The number of solar cell structural units arranged in a matrix is 5 per row and 5 per column, the thickness of the flexible substrate is 2000 μm, the thickness of the flexible packaging layer is 800 μm, and the spacing between the solar cell structural units arranged in the matrix is 500 μm, as described The thickness of the copper connecting line is 75nm and the width is 15μm. The thickness of the first layer of gold electrode in the solar cell structural unit is 40nm, the thickness of the second layer of gold electrode is 70nm, and the thickness of the horizontally arranged p-type nanowire film is 600nm. The thickness of the n-type semiconductor film is 300 nm, and the distance between the n-type semiconductor film and the first layer of gold electrode is 15 μm. The production steps are as follows:

1) Use the magnetron sputtering method to prepare a titanium electrode array with 5 rows and 5 columns and a gold electrode array with a thickness of 40nm on a silicon substrate covered with a silicon dioxide layer, as shown in Figure 2-A and Figure 3- A;

2) Apply photoresist on the surface of the substrate, and carve a rectangular window array on the surface of the substrate through UV exposure and development. The inside of the rectangular window is not covered by photoresist and the silicon dioxide layer is exposed, and the outside of the rectangular window is covered by photoresist. The inside of the rectangular window contains gold electrodes and does not contain titanium electrodes, as shown in Figure 2-B and Figure 3-B;

3) Transfer the p-type nanowires to the window area described in step 2) to form a horizontally arranged p-type nanowire film, and cover one side of the p-type nanowire film with a gold electrode, as shown in Figure 2- C and Figure 3-C;

4) Repeat step 3) three times to make the formed horizontally arranged p-type nanowire film reach 600nm, as shown in Figure 2-C and Figure 3-C;

5) Remove the photoresist outside the rectangular window, as shown in Figure 2-D and Figure 3-D;

6) Use the magnetron sputtering method to prepare a gold electrode with the same shape and size as the gold electrode described in step 1) and a thickness of 70nm at the same position of the gold electrode described in step 1), so that a p-type nanowire film One side of the electrode forms a sandwich structure with two layers of gold electrodes, as shown in Figure 2-E and Figure 3-E;

7) Use pulse laser deposition method to prepare an n-type semiconductor film with a thickness of 300nm, so that the prepared n-type semiconductor film covers part of the p-type nanowire film and covers part of the titanium electrode, and the prepared n-type semiconductor film and the gold electrode on the right side The spacing is 15μm, as shown in Figure 2-F and Figure 3-F;

8) Use magnetron sputtering to prepare copper connecting lines with a thickness of 75nm and a width of 15μm, as shown in Figure 2-G and Figure 3-G;

9) Use the spin coating method to spin-coat a flexible substrate layer with a thickness of 2000 μm on the substrate surface to cover the entire solar cell array and copper connecting lines, as shown in Figure 2-H and Figure 3-H;

10) Use the sacrificial layer etching method to peel off the flexible substrate layer and solar cell array from the silicon substrate covered with the silicon dioxide layer, as shown in Figure 2-I and Figure 3-I;

11) Use the spin coating method to spin-coat a flexible packaging layer with a thickness of 800 μm on the flexible substrate layer, so that the entire solar cell array is covered between the flexible substrate layer and the flexible packaging layer, as shown in Figure 2-J and Figure 3-J.

Example 3:

The number of solar cell structural units arranged in a matrix is 10 per row and 10 per column, the thickness of the flexible substrate is 3000 μm, the thickness of the flexible packaging layer is 1000 μm, and the spacing between the solar cell structural units arranged in a matrix is 700 μm, as described The thickness of the copper connecting wire is 150nm and the width is 20μm. The thickness of the first layer of gold electrode in the solar cell structural unit is 50nm. The thickness of the second layer of gold electrode is 100nm. The thickness of the horizontally arranged p-type nanowire film is 800nm. The thickness of the n-type semiconductor film is 500 nm, and the distance between the n-type semiconductor film and the first layer of gold electrode is 20 μm. The production steps are as follows:

1) Use magnetron sputtering to prepare a titanium electrode array with 10 rows and 10 columns and a gold electrode array with a thickness of 50nm on a silicon substrate covered with a silicon dioxide layer, as shown in Figure 2-A and Figure 3- A;

2) Apply photoresist on the surface of the substrate, and carve a rectangular window array on the surface of the substrate through UV exposure and development. The inside of the rectangular window is not covered by photoresist and the silicon dioxide layer is exposed, and the outside of the rectangular window is covered by photoresist. The inside of the rectangular window contains gold electrodes and does not contain titanium electrodes, as shown in Figure 2-B and Figure 3-B;

3) Transfer the p-type nanowires to the window area described in step 2) to form a horizontally arranged p-type nanowire film, and cover one side of the p-type nanowire film with a gold electrode, as shown in Figure 2- C and Figure 3-C;

4) Repeat step 3) four times to make the formed horizontally arranged p-type nanowire film reach 800nm, as shown in Figure 2-C and Figure 3-C;

5) Remove the photoresist outside the rectangular window, as shown in Figure 2-D and Figure 3-D;

6) Use the magnetron sputtering method to prepare a gold electrode with the same shape and size as the gold electrode described in step 1) and a thickness of 100 nm at the same position of the gold electrode described in step 1), so that a p-type nanowire film One side of the electrode forms a sandwich structure with two layers of gold electrodes, as shown in Figure 2-E and Figure 3-E;

7) Use pulse laser deposition method to prepare an n-type semiconductor film with a thickness of 500nm, so that the prepared n-type semiconductor film covers part of the p-type nanowire film and covers part of the titanium electrode, and the prepared n-type semiconductor film and the gold electrode on the right side The spacing is 20μm, as shown in Figure 2-F and Figure 3-F;

8) Use the magnetron sputtering method to prepare copper connecting lines with a thickness of 150nm and a width of 20μm, as shown in Figure 2-G and Figure 3-G;

9) Use the spin coating method to spin-coat a flexible substrate layer with a thickness of 3000 μm on the substrate surface so that it covers the entire solar cell array and copper connecting lines, as shown in Figure 2-H and Figure 3-H;

10) Use the sacrificial layer etching method to peel off the flexible substrate layer and solar cell array from the silicon substrate covered with the silicon dioxide layer, as shown in Figure 2-I and Figure 3-I;

11) Use the spin coating method to spin-coat a flexible packaging layer with a thickness of 1000 μm on the flexible substrate layer, so that the entire solar cell array is covered between the flexible substrate layer and the flexible packaging layer, as shown in Figure 2-J and Figure 3-J.

Claims (9)

1. A flexible heterojunction solar cell array based on horizontally arranged nanowire films, characterized in that: it includes a layer of flexible substrate (1), a solar cell array, and a layer of flexible packaging layer (8). The solar energy The solar cell array is disposed between a flexible substrate (1) and a flexible packaging layer (8). The solar cell array includes a matrix-arranged solar cell structural unit and a copper connection line (7). The matrix-arranged solar cell structural unit The number is greater than or equal to 2 in each row and column; The flexible heterojunction solar cell array based on horizontally arranged nanowire films is prepared according to the following sequential steps: 1) Use magnetron sputtering to prepare a titanium electrode array and a gold electrode array with a thickness of 30-50nm on a silicon substrate covered with a silicon dioxide layer; 2) Apply photoresist on the surface of the substrate, and carve a rectangular window array on the surface of the substrate through UV exposure and development. The inside of the rectangular window is not covered by photoresist and the silicon dioxide layer is exposed, and the outside of the rectangular window is covered by photoresist. The interior of the rectangular window contains gold electrodes and no titanium electrodes; 3) Transfer the p-type nanowires to the window area described in step 2) to form a horizontally arranged p-type nanowire film, and cover one side of the p-type nanowire film with a gold electrode; 4) Repeat step 3) two or more times to make the formed horizontally arranged p-type nanowire film reach 200-1000nm; 5) Remove the photoresist outside the rectangular window; 6) Use the magnetron sputtering method to prepare a gold electrode with the same shape and size as the gold electrode described in step 1) and a thickness of 50-100nm at the same position of the gold electrode described in step 1), so that the p-type nanometer One side of the line film forms a sandwich structure with two layers of gold electrodes; 7) Use pulse laser deposition method to prepare an n-type semiconductor film with a thickness of 150-500 nm, so that the prepared n-type semiconductor film covers part of the p-type nanowire film and covers part of the titanium electrode. The prepared n-type semiconductor film and its right side The distance between gold electrodes is 5-20μm; 8) Use magnetron sputtering to prepare copper connecting lines with a thickness of 50-200nm and a width of 5-20μm; 9) Use the spin coating method to spin-coat a flexible substrate layer with a thickness of 1000-3000 μm on the substrate surface to cover the entire solar cell array and copper connecting lines; 10) Use sacrificial layer etching to peel off the flexible substrate layer and solar cell array from the silicon substrate covered with the silicon dioxide layer; 11) Use the spin coating method to spin-coat a flexible encapsulation layer with a thickness of 500-1000 μm on the flexible substrate layer, so that the entire solar cell array is covered between the flexible substrate layer and the flexible encapsulation layer. 2. A flexible heterojunction solar cell array based on horizontally arranged nanowire films according to claim 1, characterized in that: the flexible substrate (1) and the flexible packaging layer (8) are PDMS, so The thickness of the flexible substrate (1) is 1000-3000 μm, and the thickness of the flexible packaging layer (8) is 500-1000 μm. 3. A flexible heterojunction solar cell array based on horizontally arranged nanowire films according to claim 1, characterized in that: the spacing of the solar cell structural units arranged in the matrix is 100 μm-1000 μm, and the copper The thickness of the connecting line (7) is 50-200nm and the width is 5-20μm. The copper connecting line includes three types: Copper connecting lines connecting the n-type semiconductor film of the upper solar cell structural unit in each column to the titanium electrode of the lower solar cell structural unit; Copper connecting lines connecting the first layer gold electrode of the upper solar cell structural unit to the first layer gold electrode of the lower solar cell structural unit in each column; The copper connection line connects the first layer gold electrode of the left solar cell structural unit in the top row of the solar cell structural units arranged in the array to the titanium electrode of the right solar cell structural unit. 4. A flexible heterojunction solar cell array based on horizontally arranged nanowire films according to claim 1, characterized in that: the solar cell structural unit is a heterojunction solar cell array based on horizontally arranged nanowire films. Battery, including a first layer of gold electrode (2), the first layer of gold electrode (2) is provided with a horizontally arranged p-type nanowire film (3), the horizontally arranged p-type nanowire film (3) One side of the p-type nanowire film (3) is covered with a first layer of gold electrode (2), and a second layer of gold electrode (4) is provided on this side. The other side of the horizontally arranged p-type nanowire film (3) is provided with a An n-type semiconductor film (5) is provided with a titanium electrode (6) on one end of the n-type semiconductor film (5). 5. A flexible heterojunction solar cell array based on horizontally arranged nanowire films according to claim 1, characterized in that: the solar cell structural units arranged in the matrix are connected by the copper connecting wires (7 ) form the solar cell array according to a specific connection method, which is that the n-type semiconductor film (5) of the upper solar cell structural unit of each column is connected to the lower solar cell through a copper connecting wire (7-1) The titanium electrode (6) of the structural unit, the first layer gold electrode (2) of the upper solar cell structural unit in each column is connected to the first layer gold electrode (2) of the lower solar cell structural unit through a copper connecting wire (7-2) ), the first layer gold electrode (2) of the left solar cell structural unit in the top row of the solar cell structural units arranged in the array is connected to the right solar cell structural unit through a copper connecting wire (7-3) Titanium electrode (6). 6. A flexible heterojunction solar cell array based on horizontally arranged nanowire films according to claim 4, characterized in that: the first layer of gold electrodes (2) and the second layer of gold electrodes ( 4) The positions are completely overlapped, the thickness of the first layer of gold electrode (2) is 30-50nm, and the thickness of the second layer of gold electrode (4) is 50-100nm. 7. A flexible heterojunction solar cell array based on a horizontally arranged nanowire film according to claim 4, characterized in that: the thickness of the horizontally arranged p-type nanowire film (3) is 200-1000nm, The p-type nanowires are p-type CdTe nanowires. 8. A flexible heterojunction solar cell array based on horizontally arranged nanowire films according to claim 4, characterized in that: the n-type semiconductor film (5) is an n-type ZnO film, and the n-type The thickness of the semiconductor film (5) is 150-500 nm, and the distance between the n-type semiconductor film (5) and the first layer gold electrode (2) is 5-20 μm. 9. A method for preparing a flexible heterojunction solar cell array based on horizontally arranged nanowire films, which is characterized in that it includes the following sequential steps: 1) Use the magnetron sputtering method to prepare a titanium electrode array and a gold electrode array with a thickness of 30-50nm on a silicon substrate covered with a silicon dioxide layer; 2) Apply photoresist on the surface of the substrate, and carve a rectangular window array on the surface of the substrate through UV exposure and development. The inside of the rectangular window is not covered by photoresist and the silicon dioxide layer is exposed, and the outside of the rectangular window is covered by photoresist. The interior of the rectangular window contains gold electrodes and no titanium electrodes; 3) Transfer the p-type nanowires to the window area described in step 2) to form a horizontally arranged p-type nanowire film, and cover one side of the p-type nanowire film with a gold electrode; 4) Repeat step 3) two or more times to make the formed horizontally arranged p-type nanowire film reach 200-1000nm; 5) Remove the photoresist outside the rectangular window; 6) Use the magnetron sputtering method to prepare a gold electrode with the same shape and size as the gold electrode described in step 1) and a thickness of 50-100nm at the same position of the gold electrode described in step 1), so that the p-type nanometer One side of the line film forms a sandwich structure with two layers of gold electrodes; 7) Use pulse laser deposition method to prepare an n-type semiconductor film with a thickness of 150-500nm, so that the prepared n-type semiconductor film covers part of the p-type nanowire film and covers part of the titanium electrode. The prepared n-type semiconductor film and its right side The distance between gold electrodes is 5-20μm; 8) Use magnetron sputtering to prepare copper connecting lines with a thickness of 50-200nm and a width of 5-20μm; 9) Use the spin coating method to spin-coat a flexible substrate layer with a thickness of 1000-3000 μm on the substrate surface to cover the entire solar cell array and copper connecting lines; 10) Use sacrificial layer etching to peel off the flexible substrate layer and solar cell array from the silicon substrate covered with the silicon dioxide layer; 11) Use the spin coating method to spin-coat a flexible encapsulation layer with a thickness of 500-1000 μm on the flexible substrate layer, so that the entire solar cell array is covered between the flexible substrate layer and the flexible encapsulation layer.