CN108493296A - A kind of flexible CdTe thin film solar cell and its preparation method and application - Google Patents

Abstract

The invention belongs to the field of photovoltaic new energy materials and devices, and discloses a flexible CdTe thin-film solar cell and a preparation method and application thereof. The present invention introduces a temporary metal substrate to deposit the functional layer of the battery at the beginning, and etches off the thin layer of the temporary metal substrate after the battery is prepared, so that the mature upper substrate structure CdTe battery can be prepared on the temporary metal substrate The process obtains flexible CdTe solar cells with lower substrate structure, which avoids the technical limitations of back contact preparation, Cu doping, CdS/CdTe heat treatment, etc. due to the deposition sequence of functional layers in the preparation of lower substrate structure cells, and is conducive to the realization of cell preparation technology. optimize.

Description

A kind of flexible CdTe thin film solar cell and its preparation method and application

technical field

The invention belongs to the field of photovoltaic new energy materials and devices, in particular to a flexible CdTe thin film solar cell and its preparation method and application.

Background technique

Cadmium telluride (CdTe) is a direct bandgap semiconductor with a bandgap width of 1.45eV, and its absorption coefficient for visible light is 100 times higher than that of silicon, so it is an ideal photovoltaic material. CdTe thin film solar cell is a thin film solar cell device based on n-CdS/p-CdTe heterojunction structure. At present, the highest laboratory conversion efficiency of CdTe solar cells is 22.1%, the module conversion efficiency is 18.6%, and the theoretical conversion efficiency can reach 33%. As one of the most competitive solar cells, CdTe thin-film solar cell has both high conversion efficiency and low cost. After nearly 20 years of rapid development, it has become the second largest product system in the current photovoltaic product market after crystalline silicon solar cells. , with great research value and market potential. It is worth pointing out that high-efficiency CdTe thin-film solar cells generally use rigid substrates, such as borosilicate glass substrates, etc. Solar cells with rigid substrates cannot meet the application requirements of many fields due to their lack of softness. As an important branch of CdTe solar cells, flexible CdTe solar cells can be integrated on windows or roofs, exterior walls or interior walls to realize building-integrated photovoltaics; they can also be applied to portable photovoltaic products, such as solar cars, solar aircraft, and solar tents , solar backpacks, etc., are important research and development directions for CdTe solar cells in the future.

Currently, the highest conversion efficiency of flexible CdTe solar cells is 16.4%, which is much lower than that of traditional CdTe solar cells based on glass substrates. Different from the upper substrate (superstrate) structure of traditional CdTe solar cells (along the direction of light incidence: glass substrate/transparent conductive layer/n-CdS/p-CdTe/back contact/metal electrode), flexible CdTe solar cells usually use the lower substrate ( substrate) structure (along the direction of light incidence: transparent conductive layer/n-CdS/p-CdTe/back contact/conductive substrate), the difference in cell structure makes flexible CdTe solar cells unable to adopt the mature preparation process of traditional CdTe solar cells, especially It is a low resistance back contact preparation process. Although some explorations have been made on the process characteristics of CdTe solar cells with a lower substrate structure, due to the limitations of the cell structure, there are technical bottlenecks that are difficult to overcome in the preparation of flexible solar cells (back contact interface engineering, CdCl ₂ "activation" heat treatment, etc.) , the performance of the device has not been effectively improved. In this context, how to innovate the fabrication process of flexible CdTe solar cells so that the structure of flexible CdTe solar cells can be compatible with the mature fabrication process of traditional substrate CdTe solar cells is a feasible and relatively cheap technical path to improve the photoelectric conversion performance of flexible CdTe solar cells .

Contents of the invention

In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a method for preparing a flexible CdTe thin film solar cell. The preparation method can adopt the mature preparation process of the traditional upper substrate structure CdTe solar cell to obtain the flexible CdTe thin film solar cell with the lower substrate structure. The battery is compatible with the mature preparation process of traditional substrate CdTe solar cells.

Another object of the present invention is to provide a flexible CdTe thin film solar cell prepared by the above method.

Another object of the present invention is to provide the application of the above-mentioned flexible CdTe thin film solar cell.

The object of the present invention is achieved through the following solutions:

A preparation method for a flexible CdTe thin film solar cell, which mainly includes the following steps:

(1) Provide a temporary metal substrate and perform cleaning pretreatment on it;

(2) Depositing a transparent conductive layer on the surface of the temporary metal substrate after cleaning and pretreatment;

(3) depositing a window layer on the transparent conductive layer;

(4) Depositing an absorbing layer on the window layer and performing heat treatment;

(5) Reactive etching is carried out to the heat-treated absorber layer, and then the back contact layer is deposited;

(6) depositing a back electrode layer on the back contact layer;

(7) A flexible substrate is provided, and the surface of the flexible substrate is bonded to the back electrode layer by adhesive;

(8) Etching and peeling off the temporary metal substrate to obtain a flexible CdTe thin film solar cell comprising a transparent conductive layer, a window layer, an absorber layer, a back contact layer, a back electrode layer, an adhesive layer, and a flexible substrate.

The temporary metal substrate described in step (1) is mainly used as a supporting substrate for depositing subsequent functional layers, and can be a cheap metal material, such as aluminum (Al), molybdenum (Mo), etc., with a thickness of 0.5 to 3 mm; The pretreatment described in (1) refers to cleaning the surface of the temporary metal substrate with a cleaning agent, then cleaning it ultrasonically, rinsing it with water, and drying it with _N2 .

The transparent conductive layer described in step (2) is SnO ₂ : F(FTO) film, and the thickness of the transparent conductive layer is 300-500nm;

The deposition of the transparent conductive layer described in step (2) can be done by magnetron sputtering FTO ceramic target.

The window layer described in step (3) is CdS or CdS:O, with a thickness of 50-200nm; the CdS described in step (3) can be prepared by chemical water bath method or magnetron sputtering method, and the described CdS :O can be obtained by reactive magnetron sputtering.

The absorbing layer described in the step (4) is a CdTe layer with a thickness of 2-6 μm; the method of depositing the absorbing layer described in the step (4) can be a close space sublimation method or a gas phase transport method.

The heat treatment described in step (4) refers to placing the sample deposited with the absorbing layer in an atmosphere containing CdCl ₂ (or MgCl ₂ ) and O ₂ for heat treatment, the heat treatment temperature is 350-420°C, and the heat treatment time is 10-30 minute. Heat treatment increases the efficiency of the battery.

The back contact layer described in step (5) is a surface p-type heavily doped layer or a high work function buffer layer formed by doping Cu on the surface of the absorbing layer CdTe;

Preferably, when the back contact layer is a surface p-type heavily doped layer formed by doping Cu on the surface of the absorbing layer CdTe, the method for depositing the back contact layer is: firstly use an etching solution to chemically etch the CdTe surface , the etching time is 5-50s, and then a thin layer of Cu is deposited by thermal evaporation or magnetron sputtering. A mixed solution of bromine and methanol, or a mixed solution of 85% phosphoric acid, 68% nitric acid and water with a volume ratio of 70:1:29;

Preferably, when the back contact layer is a high work function buffer layer, the method of depositing the back contact layer is to deposit a high work function buffer layer by thermal evaporation or magnetron sputtering, and the thickness of the high function function buffer layer is 5 ~100nm; the high work function buffer layer can be a metal telluride ( _CuxTe , ZnTe, Sb ₂ Te ₃ , ZnTe:Cu, ZnTe:N, etc., where x=1~2) or a transition metal oxide ( MoO ₃ , WO ₃ , V ₂ O ₅ , etc.).

The back electrode layer described in step (6) includes conductive materials such as metal back electrodes (Au, Mo, etc.), graphite, and when the back electrode layer is a metal back electrode, the thickness is 100 to 1000 nm; when the back electrode layer is graphite , the thickness of the back electrode is 1-10 μm;

When the back electrode layer described in the step (6) is a metal back electrode, the method for depositing the back electrode layer is thermal evaporation; when the back electrode layer described in the step (6) is graphite, the The method of depositing the back electrode layer is to coat the graphite slurry on the back contact layer, and then heat-treat at 200°C for 10-30min;

The flexible substrate material described in the step (7) can be polyimide, polycarbonate, polyethylene naphthalate, polyacrylate, polysulfone or polyethersulfone; Described viscose is preferably 3 Ton-shaped epoxy adhesive layer;

The etching stripping described in step (8) mainly adopts a dry etching process to remove the temporary metal substrate without damaging the transparent conductive layer deposited on the substrate. The specific method is to put the product in step (7) into the metal etching machine, feed the etching gas into the etching reaction chamber, adjust the gas pressure in the chamber and the bias power of the sample stage, and utilize the contact between the etching gas and the metal surface. The bombardment reaction removes the metal substrate.

The etching gas described in step (8) can be Cl ₂ , BCl ₃ , Ar, N ₂ , CHF ₃ , CH ₄ , etc.; preferably Cl ₂ .

A flexible CdTe thin film solar cell prepared by the above method.

The application of the above-mentioned flexible CdTe thin film solar cell in flexible wearable photovoltaic products, photovoltaic building integration, portable photovoltaic products and other bending and folding photovoltaic products.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

The present invention introduces a temporary metal substrate to deposit the functional layer of the battery at the beginning, and etches off the thin layer of the temporary metal substrate after the battery is prepared, so that the mature upper substrate structure CdTe battery can be prepared on the temporary metal substrate The flexible CdTe solar cell with the lower substrate structure is obtained by the process, which avoids the technical limitations of back contact preparation, Cu doping, CdS/CdTe heat treatment, etc. caused by the deposition sequence of the functional layer in the preparation of the lower substrate structure cell, which is conducive to the realization of the battery preparation technology. optimize.

Description of drawings

Fig. 1 is the current-voltage curve of the CdTe solar cell prepared in Example 2 under standard light intensity (AM1.5G, 1000W/m ² ).

Detailed ways

The present invention will be further described in detail below with reference to the examples and drawings, but the implementation of the present invention is not limited thereto.

The reagents used in the examples can be routinely purchased from the market unless otherwise specified.

Example 1

(1) Use an aluminum sheet with a thickness of 2 mm as a temporary substrate, and use an aluminum cleaning solution to clean the aluminum surface. The ultrasonic cleaning time is 5 minutes, then rinse it with deionized water, and dry it with _N2 .

(2) The transparent conductive oxide SnO ₂ :F(FTO) is deposited on the surface of the aluminum substrate by magnetron sputtering, and the film thickness is about 500nm. Using magnetron sputtering to sputter SnO ₂ :F target (mixed SnO ₂ and SnF ₂ powder hot-pressed target with a molar ratio of 10:1) under Ar atmosphere, the substrate temperature is 200°C, and the sputtering power is 90W , sputtering time 30min.

(3) CdS was deposited on the surface of FTO by the chemical water bath (CBD) method, the reaction precursors were ammonium acetate (0.7708g), cadmium acetate (0.1333g) and thiourea (0.1903g), the solution volume was 500mL, and the reaction deposition temperature was 80°C, the deposition time is 30 minutes, and the thickness of the CdS layer is 100nm.

(4) A CdTe thin film was grown on the surface of CdS by the close-space sublimation (CSS) method, the growth temperature was 550° C., the growth time was 5 minutes, and the thickness was about 5 μm.

(5) Place the above laminate in an atmosphere environment containing CdCl ₂ and O ₂ for heat treatment, the heat treatment temperature is 400° C., and the heat treatment time is 10 minutes.

(6) Put the above sample into phosphoric acid nitric acid solution (volume ratio: 68% nitric acid: 85% phosphoric acid: water = 1:70:29) and etch for 50 seconds, after the etching is completed, rinse the surface of the sample with deionized water , and then blow dry with _N2 .

(7) Put the etched sample into a vacuum chamber with a vacuum degree of 5× ^10-6 Pa, fix the mask on the surface of the sample, and deposit a 2nm-thick Cu metal layer on the surface of the sample by electron beam evaporation. Then a 200 nm thick Au electrode was deposited by vacuum thermal evaporation.

(8) Using the polyacrylate substrate as a flexible substrate, apply the same amount of A glue and B glue of 3 tons of epoxy glue on the clean flexible substrate evenly, and then apply the above steps (7) ) in which the surface of the Au electrode is laminated on the surface of the flexible substrate coated with adhesive, and cured for 3 hours to ensure that the 3-ton epoxy adhesive is completely cured, and the Au electrode is firmly laminated on the flexible substrate.

(9) Put the aluminum substrate sample in step (1) into the metal etching reaction chamber, feed Cl ₂ with a pressure of 10 mTorr, adjust the bias power of the dual radio frequency power source to 80W, and the source power to 40W, Use Cl ₂ and aluminum surface contact bombardment to carry out reactive etching, and the reaction time is 40 minutes. Since Cl ₂ and FTO cannot react, the aluminum substrate can be completely removed, and then the “FTO/CdS/CdTe/Cu‐Au/ Flexible CdTe solar cells with flexible substrate" structure.

Example 2

(1) Use an aluminum sheet with a thickness of 1mm as a temporary substrate, clean the aluminum surface with an aluminum cleaning solution, and ultrasonically clean it for 5 minutes, then rinse it with deionized water, and dry it with _N2 .

(2) The transparent conductive oxide SnO ₂ :F(FTO) is deposited on the surface of the aluminum substrate by magnetron sputtering, and the film thickness is about 300nm. Using magnetron sputtering to sputter SnO ₂ :F target (mixed SnO ₂ and SnF ₂ powder hot-pressed target with a molar ratio of 10:1) under Ar atmosphere, the substrate temperature is 200°C, and the sputtering power is 90W , sputtering time 20min.

(3) CdS was deposited on the surface of FTO by the chemical water bath (CBD) method, the reaction precursors were ammonium acetate (0.7708g), cadmium acetate (0.1333g) and thiourea (0.1903g), the solution volume was 500mL, and the reaction deposition temperature was 80°C, the deposition time is 30 minutes, and the thickness of the CdS layer is 100nm.

(4) A CdTe thin film was grown on the surface of CdS by the close-space sublimation (CSS) method, the growth temperature was 550° C., the growth time was 5 minutes, and the thickness was about 5 μm.

(5) Place the above laminate in an atmosphere environment containing CdCl ₂ and O ₂ for heat treatment, the heat treatment temperature is 400° C., and the heat treatment time is 10 minutes.

(6) Put the above sample into phosphoric acid nitric acid solution (volume ratio: 68% nitric acid: 85% phosphoric acid: water = 1:70:29) and etch for 50 seconds, after the etching is completed, rinse the surface of the sample with deionized water , and then blow dry with _N2 .

(7) Put the etched sample into a vacuum chamber with a vacuum degree of 5× ^10-5 Pa, fix the mask on the surface of the sample, and deposit ZnTe with a thickness of 200 nm on the surface of the sample by double-source co-evaporation method: The Cu back contacted the buffer layer, and then a 200nm thick Au electrode was deposited by thermal evaporation.

(8) Using the polyacrylate substrate as a flexible substrate, apply the same amount of A glue and B glue of 3 tons of epoxy glue on the clean flexible substrate evenly, and then apply the above steps (7) ) in which the surface of the Au electrode is laminated on the surface of the flexible substrate coated with adhesive, and cured for 3 hours to ensure that the 3-ton epoxy adhesive is completely cured, and the Au electrode is firmly laminated on the flexible substrate.

(9) Put the aluminum substrate sample in step (1) into the metal etching reaction chamber, feed Cl ₂ with a pressure of 10 mTorr, adjust the bias power of the dual radio frequency power source to 80W, and the source power to 40W, Use Cl ₂ and aluminum surface contact bombardment to carry out reactive etching, the reaction time is 40 minutes, because Cl ₂ and FTO cannot react, so after the aluminum substrate is completely removed, then you can get "FTO/CdS/CdTe/ZnTe:Cu/ Flexible CdTe solar cells with Au/flexible substrate structure.

The current-voltage curve of the CdTe solar cell prepared in Example 2 under standard light intensity (AM1.5G, 1000W/m ² ) is shown in Figure 1. From Figure 1, it can be concluded that the performance parameters of the battery are: open circuit The voltage is 0.777V, the short-circuit current density is 23.2mA/cm2, the fill factor is 68.9%, and the photoelectric conversion efficiency of the cell is 12.4%. It shows that based on the structural design of the present invention, it is possible to prepare a high-efficiency flexible CdTe solar cell with a lower substrate structure by adopting the mature preparation process of the traditional upper substrate CdTe solar cell.

Example 3

(1) Use an aluminum sheet with a thickness of 0.5 mm as a temporary substrate, and use an aluminum cleaning solution to clean the aluminum surface. The ultrasonic cleaning time is 5 minutes, then rinse it with deionized water, and dry it with _N2 .

(2) The transparent conductive oxide SnO ₂ :F(FTO) is deposited on the surface of the aluminum substrate by magnetron sputtering, and the film thickness is about 300nm. Using magnetron sputtering to sputter SnO ₂ :F target (mixed SnO ₂ and SnF ₂ powder hot-pressed target with a molar ratio of 10:1) under Ar atmosphere, the substrate temperature is 200°C, and the sputtering power is 90W , sputtering time 20min.

(3) CdS was deposited on the surface of FTO by the chemical water bath (CBD) method. The reaction precursors were ammonium acetate, cadmium acetate and thiourea ammonium acetate (0.7708g), cadmium acetate (0.1333g) and thiourea (0.1903g). The volume is 500mL, the reaction deposition temperature is 80°C, the deposition time is 30 minutes, and the thickness of the CdS layer is 100nm.

(4) A CdTe thin film was grown on the surface of CdS by the close-space sublimation (CSS) method, the growth temperature was 550°C, the growth time was 5 minutes, and the thickness was about 3 μm.

(5) Place the above laminate in an atmosphere containing CdCl ₂ and O ₂ for heat treatment, the heat treatment temperature is 390° C., and the heat treatment time is 10 minutes.

(6) Put the above sample into bromine methanol solution (volume ratio: bromine/methanol=1/500) and etch for 50 seconds. After the etching is completed, rinse the surface of the sample with deionized water, and then dry it with _N2 .

(7) Put the etched sample into a vacuum chamber with a vacuum degree of 5× ^10-5 Pa, fix the mask on the surface of the sample, and deposit a high work function transition film with a thickness of 20 nm on the surface of the sample by vacuum thermal evaporation. Metal oxide _MoO3 was used as the back contact buffer layer, and then a 200 nm thick Au electrode was deposited by thermal evaporation.

(8) Using the polyimide substrate as a flexible substrate, apply the same amount of A glue and B glue of 3 tons of epoxy glue on the clean flexible substrate evenly, and then apply the above steps ( 7) The surface of the Au electrode is laminated on the surface of the flexible substrate coated with adhesive, and cured for 3 hours to ensure that the 3-ton epoxy adhesive is completely cured, and the Au electrode is firmly laminated on the flexible substrate.

(9) Put the aluminum substrate sample in step (1) into the metal etching reaction chamber, feed Cl ₂ with a pressure of 10 mTorr, adjust the bias power of the dual radio frequency power source to 80W, and the source power to 40W, Use Cl ₂ and aluminum surface contact bombardment to carry out reactive etching, and the reaction time is 40 minutes. Since Cl ₂ and FTO cannot react, the aluminum substrate can be completely removed, and then the “FTO/CdS/CdTe/Cu‐Au/ Flexible CdTe solar cells with flexible substrate" structure.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. a kind of preparation method of flexible CdTe thin film solar cell, it is characterised in that mainly include the following steps that：

(1) Temporary Met substrate is provided and cleaning pretreatment is carried out to it；

(2) pretreated Temporary Met substrate surface deposition transparency conducting layer is being cleaned；

(3) Window layer is deposited over transparent conductive layer；

(4) the deposit absorbent layer in Window layer, and be heat-treated；

(5) reactive ion etching is carried out to the absorbed layer after heat treatment, then deposits back contact；

(6) back electrode layer is deposited on back contact；

(7) flexible substrate is provided, and the surface of flexible substrate is fitted in by viscose glue on back electrode layer；

(8) etching peels off Temporary Met substrate, obtains comprising transparency conducting layer, Window layer, absorbed layer, back contact, back of the body electricity The flexible CdTe thin film solar cell of pole layer, adhesive-layer, flexible substrate.

2. the preparation method of flexible CdTe thin film solar cell according to claim 1, it is characterised in that：

Temporary Met substrate described in step (1) is cheap metal material, and thickness is 0.5~3mm；

Transparency conducting layer described in step (2) is FTO films, and the thickness of transparency conducting layer is 300-500nm；

Window layer described in step (3) is CdS or CdS:O, thickness are 50~200nm；

Absorbed layer described in step (4) is CdTe layer, and thickness is 2~6 μm；

Back contact described in step (5) is that the surface p-type heavily doped layer or high work function to be formed are adulterated to CdTe surface Cs u Buffer layer, when back contact is to adulterate the surface p-type heavily doped layer to be formed to CdTe surface Cs u, thickness of the Cu on the surfaces CdTe For 2~5nm；When back contact is high work function buffer layer, thickness 5-100nm；

Back electrode layer described in step (6) is metal back electrode or graphite, and when back electrode layer is metal back electrode, thickness is 100~1000nm；When back electrode layer is graphite, back electrode thickness is 1~10 μm；

Flexible substrate material described in step (7) is polyimides, makrolon, polyethylene naphthalate, polypropylene Acid esters, polysulfones or polyether sulfone；The viscose glue is 3 tons of type epoxy adhesive layers.

3. the preparation method of flexible CdTe thin film solar cell according to claim 2, it is characterised in that：

High work function buffer layer described in step (5) is metal telluride or transition metal oxide；

Metal back electrode described in step (6) is Au or Mo.

4. the preparation method of flexible CdTe thin film solar cell according to claim 3, it is characterised in that：

Metal telluride described in step (5) is Cu_xTe、ZnTe、Sb₂Te₃、ZnTe:Cu or ZnTe:N, wherein x=1-2；

Transition metal oxide described in step (5) is MoO₃、WO₃Or V₂O₅。

5. the preparation method of flexible CdTe thin film solar cell according to claim 2, it is characterised in that：

Pretreatment described in step (1) refers to being cleaned to Temporary Met substrate surface with cleaning agent, is then cleaned by ultrasonic, It is rinsed with water again totally, N is used in combination₂Drying；

Deposition transparency conducting layer described in step (2) is realized by magnetron sputtering FTO ceramic targets；

CdS described in step (3) is prepared by chemical bath method or magnetron sputtering method, the CdS:O is by reacting magnetic control Sputtering method obtains；

The method of deposit absorbent layer described in step (4) is close spaced sublimation method or vapor transportation method；

Back contact described in the step (5) is when adulterating the surface p-type heavily doped layer to be formed to absorbed layer CdTe surface Cs u, Deposition back contact method be：Chemical etching is carried out to the surfaces CdTe using etching liquid, etch period 5-50s is then warm Evaporation or magnetron sputtering method deposit Cu thin layers, and thickness of the Cu on the surfaces CdTe is 2~5nm；It is 1 that wherein etching liquid, which is volume ratio,: 1000-1:100 bromine and the mixed solution of methanol or volume ratio are 70:1:The mixing of 29 85% phosphoric acid, 68% nitric acid and water Solution；

When back contact described in the step (5) is high work function buffer layer, the method for depositing back contact is to be steamed using heat Hair or magnetron sputtering method deposit high work function buffer layer, and the thickness of high power function buffer layer is 5~100nm；

When back electrode layer described in the step (6) is metal back electrode, the method for the deposition back electrode layer is thermal evaporation Method；When back electrode layer described in the step (6) is graphite, graphite slurry is is coated by the method for the deposition back electrode layer On back contact, 10~30min is then heat-treated at 200 DEG C.

6. the preparation method of flexible CdTe thin film solar cell according to claim 1, it is characterised in that：

Heat treatment described in step (4), which refers to, is placed in the sample that deposited absorbed layer containing CdCl₂And O₂Or MgCl₂And O₂'s It is heat-treated under atmosphere, heat treatment temperature is 350~420 DEG C, and heat treatment time is 10~30 minutes.

7. the preparation method of flexible CdTe thin film solar cell according to claim 1, it is characterised in that：

The specific method of etching stripping described in step (8) is that the product in step (7) is put into metal etch board, to quarter Erosion reaction chamber is passed through etching gas, gas pressure intensity sample stage bias power in adjusting cavity, utilizes etching gas and metal surface Bombardment reaction removal metal substrate.

8. the preparation method of flexible CdTe thin film solar cell according to claim 7, it is characterised in that：

Etching gas described in step (8) is Cl₂、BCl₃、Ar、N₂、CHF₃、CH₄。

9. a kind of flexible CdTe thin film solar cell being prepared according to claim 1-8 any one of them methods.

10. flexible CdTe thin film solar cell according to claim 9 is in flexible wearable photovoltaic products, photovoltaic building one Application in body, Portable photovoltaic product and other bending fold class photovoltaic products.