Perovskite solar cell with high efficient hole transport layer of undoped nickel chlorophyll derivative and preparation method thereof

Abstract

The present application relates to a kind of high-efficiency hole transport layer of undoped nickel chlorophyll derivative perovskite solar cell and its preparation method, belong to perovskite solar cell field.The perovskite solar cell includes from bottom to top:transparent conductive glass anode, hole transport layer, perovskite layer, electron transport layer, hole blocking layer and metal cathode;The hole transport layer is polymeric chlorophyll film Poly (NiChl-Deoxo) or Poly (NiChl-CN).The present application uses undoped nickel chlorophyll derivative as hole transport layer, which significantly improves the energy conversion efficiency of perovskite solar cell, and makes it reach the highest power conversion efficiency of 21.8%.The perovskite solar cell of the present application shows excellent stability under long-term test.After 2600 hours of environmental exposure test, the device can still maintain 95% of the initial efficiency, showing good durability and reliability, suitable for long time use.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cells (PSCs), and in particular to a perovskite solar cell with a high-efficiency hole transport layer without a doped nickel chlorophyll derivative and a preparation method thereof. Background Art

[0002] Among emerging photovoltaic technologies, perovskite solar cells (PSCs) have attracted widespread attention due to their rapidly increasing energy conversion efficiencies. To date, the highest PSCs have exceeded 26%. Inverse-structured PSCs have attracted significant attention due to their advantages, including low hysteresis in the current-voltage curve, excellent stability, and low manufacturing costs. The hole transport layer plays a key role in improving the efficiency and stability of PSCs. Therefore, the development of high-performance, undoped PSCs is crucial to enhance device reproducibility and lifetime.

[0003] Chlorophyll (Chl) and its structurally related compounds are widely present in nature and have unique photoelectric properties. Therefore, people use them as hole transport materials for perovskite solar cells. For example, Chinese patent document CN116828941A discloses a perovskite solar cell based on an electropolymerized chlorophyll hole transport layer and its preparation method. The electrochemically polymerized chlorophyll film prepared by electrochemically polymerizing chlorophyll containing unsaturated bonds is used as a high-efficiency perovskite solar cell with a photoelectric conversion efficiency as high as 19.0%. However, current research based on undoped chlorophyll materials is still limited, resulting in a maximum power conversion efficiency (PCE) of only 19% for perovskite solar cells, which limits its application in perovskite solar cells. Summary of the Invention

[0004] The present invention aims to solve the technical problems in the prior art and provides a perovskite solar cell with an efficient hole transport layer without doping with nickel chlorophyll derivatives and a preparation method thereof. The present invention uses natural chlorophyll-a for modification, designing the C13 position to have a nickel chlorophyll without a carbonyl group (NiChl-Deoxo) and a nickel chlorophyll containing dicyanovinyl (NiChl-CN), respectively. These are prepared as the hole transport layer of the perovskite solar cell through electrochemical polymerization. The resulting perovskite solar cell has high energy conversion efficiency and stability.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A perovskite solar cell with an efficient hole transport layer without doping nickel chlorophyll derivatives, comprising, from bottom to top, a transparent conductive glass anode, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and a metal cathode;

[0007] Characterized in that the hole transport layer is a polymerized chlorophyll film Poly(NiChl-Deoxo) or Poly(NiChl-CN);

[0008] The structural formulas of chlorophyll monomers NiChl-Deoxo and NiChl-CN are as follows:

[0009]

[0010] In the above technical solution, the hole transport layer is a polymerized chlorophyll film Poly (NiChl-Deoxo) or Poly (NiChl-CN) prepared by electrochemical polymerization.

[0011] In the above technical solution, the transparent conductive glass anode is made of indium tin oxide (ITO) material, and the perovskite layer is Cs 0.05 FA 0.85 MA 0.1 PbI3, the electron transport layer is C 60 , the hole blocking layer is bathocuproine (BCP) and the metal cathode is silver (Ag).

[0012] In the above technical solution, the thickness of the hole transport layer is 8-12nm, the thickness of the perovskite layer is 540-560nm, the thickness of the electron transport layer is 20-25nm, the thickness of the hole blocking layer is 6-8nm, and the thickness of the metal cathode is 50-70nm.

[0013] A method for preparing a perovskite solar cell with an efficient hole transport layer without a nickel-doped chlorophyll derivative comprises the following steps:

[0014] 1) Pre-treating the transparent conductive glass anode with ultraviolet ozone;

[0015] 2) preparing a hole transport layer on the transparent conductive glass;

[0016] 3) Spin-coating a perovskite layer on the hole transport layer;

[0017] 4) evaporating an electron transport layer, a hole blocking layer and a metal cathode on the perovskite layer;

[0018] It is characterized in that the step 2) comprises the following steps:

[0019] The hole transport layer is a polymerized chlorophyll film Poly (NiChl-Deoxo) or Poly (NiChl-CN) prepared by electrochemical polymerization;

[0020] A chlorophyll monomer NiChl-Deoxo or NiChl-CN solution is prepared as an electrolyte, and the hole transport layer is prepared by electrochemical deposition on the transparent conductive glass substrate obtained in step 1) using a potentiodynamic method.

[0021] In the above technical solution, the steps of preparing the chlorophyll monomer NiChl-Deoxo or NiChl-CN solution in step 2) are as follows:

[0022] Chlorophyll monomer NiChl-Deoxo or NiChl-CN and tetrabutylammonium hexafluorophosphate are dissolved in dichloromethane to obtain a chlorophyll monomer NiChl-Deoxo or NiChl-CN solution.

[0023] In the above technical solution, the mass volume ratio of the tetrabutylammonium hexafluorophosphate, chlorophyll monomer and dichloromethane is: 1g:8.5mg:25mL.

[0024] In the above technical solution, the steps of preparing the hole transport layer by electrochemical deposition on the transparent conductive glass substrate obtained in step 1) using a potentiodynamic method in step 2) are as follows:

[0025] The transparent conductive glass substrate obtained in step 1) is placed in a three-electrode system as a working electrode, a platinum sheet is used as a counter electrode, an Ag / AgCl electrode is used as a reference electrode, and a chlorophyll monomer NiChl-Deoxo or NiChl-CN solution is used as an electrolyte. Cyclic voltammetry is used for electrochemical polymerization to prepare the hole transport layer.

[0026] In the above technical solution, the parameters of electrochemical polymerization are set as follows: maximum potential 1.3V, minimum potential 0V, starting potential 0V, scanning speed 100mV s -1 , the number of electrochemical cycles is 25.

[0027] In the above technical solution, after the polymerization is completed in step 2), the substrate is cleaned with dichloromethane and vacuum dried for later use.

[0028] The beneficial effects of the present invention are:

[0029] The present invention uses natural chlorophyll-a for modification, designing the C13 position to be nickel chlorophyll without carbonyl group (NiChl-Deoxo) and nickel chlorophyll containing dicyanovinyl group (NiChl-CN), and prepares them into the hole transport layer of perovskite solar cells through electrochemical polymerization. The obtained perovskite solar cell has high energy conversion efficiency and stability.

[0030] The present invention significantly improves the energy conversion efficiency of perovskite solar cells by using an undoped nickel chlorophyll derivative as a hole transport layer, achieving a peak power conversion efficiency (PCE) of 21.8%, the highest reported value for chlorophyll-based materials to date. The perovskite solar cells of the present invention exhibit excellent stability under long-term testing. After 2,600 hours of environmental exposure testing, the devices still maintained 95% of their initial efficiency, demonstrating excellent durability and reliability, making them suitable for long-term use.

[0031] The preparation method of the perovskite solar cell based on the electropolymerized chlorophyll hole transport layer of the present invention has the advantages of a simple and easy synthesis process, low equipment requirements, and good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Figure 1 This is a structural diagram of a high-efficiency perovskite solar cell device based on undoped nickel chlorophyll as a hole transport layer in the comparative examples and embodiments of the present invention.

[0034] Figure 2 It is a current-voltage (JV) curve of a high-efficiency perovskite solar cell device based on undoped nickel chlorophyll as a hole transport layer in the comparative example and embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention discloses a perovskite solar cell with an efficient hole transport layer without doping nickel chlorophyll derivatives, comprising, from bottom to top, a transparent conductive glass anode, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer, and a metal cathode; the hole transport layer is a polymerized chlorophyll film Poly(NiChl-Deoxo) or Poly(NiChl-CN), which is prepared by electrochemical polymerization;

[0036] The structural formula of chlorophyll monomer NiChl-Deoxo or NiChl-CN is as follows:

[0037]

[0038] In the present invention, the chlorophyll monomer is a chlorophyll derivative containing an unsaturated bond, and the polymerized chlorophyll film prepared by electrochemical polymerization is defined as an electropolymerized chlorophyll film: the chlorophyll film prepared by electrochemical deposition on a substrate using a potentiodynamic method using a configured chlorophyll monomer solution as an electrolyte.

[0039] Preferably, the transparent conductive glass anode is made of indium tin oxide (ITO) material, and the perovskite layer is made of Cs 0.05 FA0.85 MA 0.1 PbI3, the electron transport layer is C 60 , the hole blocking layer is bathocuproine (BCP) and the metal cathode is silver (Ag).

[0040] The present invention has no special requirements for the thickness of each layer of the perovskite solar cell; the desired thickness can be prepared according to actual needs. Preferably, the hole transport layer has a thickness of 8-12 nm, the perovskite layer has a thickness of 540-560 nm, the electron transport layer has a thickness of 20-25 nm, the hole blocking layer has a thickness of 6-8 nm, and the metal cathode has a thickness of 50-70 nm.

[0041] The method for preparing a perovskite solar cell with an efficient hole transport layer without a nickel-doped chlorophyll derivative of the present invention comprises the following steps:

[0042] 1) Pre-treating the transparent conductive glass anode with ultraviolet ozone;

[0043] 2) preparing a hole transport layer on the transparent conductive glass;

[0044] 3) Spin-coating a perovskite layer on the hole transport layer;

[0045] 4) evaporating an electron transport layer, a hole blocking layer and a metal cathode on the perovskite layer;

[0046] Described step 2) comprises the following steps:

[0047] The hole transport layer is a polymerized chlorophyll film Poly (NiChl-Deoxo) or Poly (NiChl-CN) prepared by electrochemical polymerization;

[0048] A chlorophyll monomer NiChl-Deoxo or NiChl-CN solution is prepared as an electrolyte, and the hole transport layer is prepared by electrochemical deposition on the transparent conductive glass substrate obtained in step 1) using a potentiodynamic method.

[0049] Preferably, a specific implementation of step 2) is:

[0050] Dissolving chlorophyll monomer NiChl-Deoxo or NiChl-CN and tetrabutylammonium hexafluorophosphate in dichloromethane to obtain a chlorophyll monomer solution;

[0051] The transparent conductive glass substrate obtained in step 1) is placed in a three-electrode system as a working electrode, a platinum sheet is used as a counter electrode, an Ag / AgCl electrode is used as a reference electrode, and the above-prepared chlorophyll monomer solution is used as an electrolyte. Cyclic voltammetry is used for electrochemical polymerization to prepare the hole transport layer.

[0052] More preferably, the chlorophyll solution is obtained by dissolving 1 g of tetrabutylammonium hexafluorophosphate and 8.5 mg of chlorophyll monomer in 25 mL of dichloromethane.

[0053] Further preferably, the parameters of electrochemical polymerization are set as follows: maximum potential 1.3 V, minimum potential 0 V, starting potential 0 V, scanning rate 100 mV s -1 , the number of electrochemical cycles is 25.

[0054] Further preferably, after the polymerization in step 2) is completed, the substrate is cleaned with dichloromethane and vacuum dried for later use.

[0055] A specific embodiment of the method for preparing a perovskite solar cell with an efficient hole transport layer without doping nickel chlorophyll derivatives of the present invention is as follows:

[0056] 1) Treatment of transparent conductive glass anode:

[0057] The cleaned transparent conductive glass was subjected to UV-ozone pretreatment for 20 minutes;

[0058] 2) Preparation and treatment of hole transport layer:

[0059] The transparent conductive glass pretreated with UV-ozone in step 1) was placed in a three-electrode system as the working electrode, with a platinum sheet as the counter electrode and an Ag / AgCl electrode as the reference electrode. The electrolyte consisted of 1 g of tetrabutylammonium hexafluorophosphate and 8.5 mg of chlorophyll monomer dissolved in 25 mL of dichloromethane. Electrochemical polymerization was performed using cyclic voltammetry with the following parameters: maximum potential of 1.3 V, minimum potential of 0 V, starting potential of 0 V, and a scan rate of 100 mV s. -1 The number of electrochemical cycles was 25. After polymerization, the film was thoroughly rinsed with dichloromethane and vacuum dried for later use;

[0060] 3) Preparation of perovskite layer:

[0061] Place the device from step 2) in an argon-filled glove box and spin-coat the hole transport layer with the perovskite precursor solution. Spin coating is performed at 1000 rpm / min for 10 seconds, then increasing to 5000 rpm / min for 40 seconds. Add 250 μL of chlorobenzene dropwise 5 seconds before the end of spin coating. After spin coating, anneal the device on a hot plate at 100°C for 30 minutes.

[0062] 4) Preparation of electron transport layer, hole blocking layer and metal cathode:

[0063] Using vacuum evaporation coating machine at a pressure less than 6×10 -4An electron transport layer, a hole blocking layer and a metal cathode are evaporated on the perovskite layer at 0.1 Pa, with an evaporation rate of 0.1 A / s

[0064] The perovskite precursor solution of the present application is Cs 0.05 FA 0.85 MA 0.1 PbI3 solution, and the preparation process is as follows:

[0065] In a nitrogen glove box, 19.5 mg of CsI, 219.3 mg of FAI, 23.8 mg of MAI, 12.66 mg of MACl and 760.7 mg of PbI2 (10% excess) are dissolved in 1 mL of DMF / DMSO solution with a volume ratio of 4:1, and stirred at room temperature for 3 hours.

[0066] In order to have a deeper understanding of the present application, the technical solutions will be described clearly and completely in combination with the examples below, but the examples of the present application are only for explaining the present application, and all other examples obtained by the person skilled in the art without making creative efforts shall belong to the protection scope of the present application.

[0067] The raw materials used in the following examples are all commercially available.

[0068] Example

[0069] 1) The etched ITO is sequentially treated with ITO cleaning agent, deionized water, acetone, alcohol, isopropanol for 30 minutes; the cleaned transparent conductive glass is subjected to ultraviolet ozone pretreatment for 20 minutes;

[0070] 2) 1 g of tetrabutylammonium hexafluorophosphate and 8.5 mg of chlorophyll monomer NiChl-Deoxo or NiChl-CN are respectively dissolved in 25 mL of dichloromethane to prepare the electrolyte required for electrochemical polymerization of chlorophyll, and the electrolyte is stirred for 2 hours; the transparent conductive glass subjected to ultraviolet ozone pretreatment for 20 minutes is used as a working electrode in a three-electrode system, with a platinum sheet as a counter electrode and an Ag / AgCl electrode as a reference electrode. The electrochemical polymerization is carried out by cyclic voltammetry, with the parameters set as: the highest potential is 1.3 V, the lowest potential is 0 V, the initial potential is 0 V, the scanning speed is 100 mV s -1 , and the number of polymerization circles is 25. After polymerization, the film is thoroughly washed with dichloromethane and vacuum dried for standby use.

[0071] 3) In an argon glove box, Cs 0.05 FA 0.85 MA 0.1For the PbI3 precursor solution, 19.5 mg of CsI, 219.3 mg of FAI, 23.8 mg of MAI, 12.66 mg of MACl, and 760.7 mg of PbI2 (10% excess) were dissolved in 1 mL of a 4:1 volume ratio DMF / DMSO solution and stirred at room temperature for 3 hours. The substrate was placed in a glove box and the perovskite precursor solution was spin-coated on the hole transport layer. The spin-coating process was as follows: first, spin-coating at 1000 rpm / min for 10 seconds, then increasing to 5000 rpm / min for 40 seconds. 250 μL of chlorobenzene was added dropwise 5 seconds before the end of the spin-coating. After the spin-coating, the substrate was placed on a hot plate for annealing at 100°C for 30 minutes.

[0072] 4) Finally, the substrate is sent into the organic evaporation deposition machine. When the pressure in the chamber is lower than 6×10 -4 Pa evaporation electron transport layer C 60 , hole blocking layer Bathocuproine (BCP) and metal cathode silver, the evaporation rate of which is The silver film thickness is 60nm. Thus, a perovskite solar cell based on Poly (NiChl-Deoxo) and Poly (NiChl-CN) as the hole transport layer is obtained. The device structure is as follows Figure 1 As shown. In this embodiment, the thickness of the hole transport layer is 10 nm, the thickness of the perovskite layer is 560 nm, the thickness of the electron transport layer is 20 nm, the thickness of the hole blocking layer is 6 nm, and the thickness of the metal cathode is 60 nm. The thickness of each layer can actually be any value within the aforementioned limited range, and only preferred thickness values ​​are given here.

[0073] Comparative Example

[0074] The hole transport layer material in this comparative example is unmodified chlorophyll (NiChl-Oxo), whose C13 position is the carbonyl group of natural chlorophyll-a and has not been treated. For comparison, this chlorophyll material was prepared into a polymerized chlorophyll film by electrochemical polymerization and used as the hole transport layer of the perovskite solar cell;

[0075] The structural formula of NiChl-Oxo is as follows:

[0076]

[0077] The specific steps include:

[0078] 1) The etched ITO was ultrasonically treated with ITO cleaning agent, deionized water, acetone, alcohol, and isopropyl alcohol for 30 minutes in sequence; the cleaned transparent conductive glass was pretreated with UV ozone for 20 minutes;

[0079] 2) Dissolve 1g of tetrabutylammonium hexafluorophosphate and 8.5mg of chlorophyll monomer NiChl-Oxo in 25mL of dichloromethane to prepare the electrolyte required for electropolymerization of chlorophyll. Stir the electrolyte for 2 hours. A transparent conductive glass pretreated with UV-ozone for 20 minutes was placed as the working electrode in a three-electrode system, with a platinum sheet as the counter electrode and an Ag / AgCl electrode as the reference electrode. Electrochemical polymerization was performed using cyclic voltammetry with the following parameters: maximum potential 1.3V, minimum potential 0V, starting potential 0V, and a scan rate of 100mVs. -1 The number of polymerization cycles was 25. After polymerization, the film was thoroughly rinsed with dichloromethane and vacuum dried for later use.

[0080] 3) Prepare Cs in an argon glove box 0.05 FA 0.85 MA 0.1 For the PbI3 precursor solution, 19.5 mg of CsI, 219.3 mg of FAI, 23.8 mg of MAI, 12.66 mg of MACl, and 760.7 mg of PbI2 (10% excess) were dissolved in 1 mL of a 4:1 volume ratio DMF / DMSO solution and stirred at room temperature for 3 hours. The substrate was placed in a glove box and the perovskite precursor solution was spin-coated on the hole transport layer. The spin-coating process was as follows: first, spin-coating at 1000 rpm / min for 10 seconds, then increasing to 5000 rpm / min for 40 seconds. 250 μL of chlorobenzene was added dropwise 5 seconds before the end of the spin-coating. After the spin-coating, the substrate was placed on a hot plate for annealing at 100°C for 30 minutes.

[0081] 4) Finally, the substrate is sent into the organic evaporation deposition machine. When the pressure in the chamber is lower than 6×10 -4 Pa evaporation electron transport layer C 60 , hole blocking layer Bathocuproine (BCP) and metal cathode silver, the evaporation rate of which is The silver film thickness is 60nm. Thus, a perovskite solar cell based on Poly (NiChl-Oxo) as the hole transport layer is obtained. The device structure is as follows Figure 1 The thickness of the hole transport layer is 10 nm, the thickness of the perovskite layer is 560 nm, the thickness of the electron transport layer is 20 nm, the thickness of the hole blocking layer is 6 nm, and the thickness of the metal cathode is 60 nm.

[0082] Table 1 shows the photovoltaic parameters of the perovskite solar cell devices prepared in the examples of the present invention and the comparative examples using Poly(NiChl-Oxo), Poly(NiChl-Deoxo) and Poly(NiChl-CN) as hole transport layers, respectively.

[0083] Table 1

[0084]

[0085] Figure 1 It is a structural diagram of a perovskite solar cell device based on Poly(NiChl-Oxo), Poly(NiChl-Deoxo) and Poly(NiChl-CN) as a hole transport layer prepared in the comparative examples and embodiments of the present invention.

[0086] Figure 2 The following are current-voltage (JV) curves of high-efficiency perovskite solar cell devices using Poly(NiChl-Oxo), Poly(NiChl-Deoxo), and Poly(NiChl-CN) as hole transport layers in comparative examples and embodiments of the present invention, and the data correspond to Table 1. Compared with perovskite solar cells with an unmodified electropolymerized chlorophyll hole transport layer at the C13 position (Poly(NiChl-Oxo)), the perovskite solar cells based on electropolymerized chlorophyll hole transport layers modified with substituents at the C13 position (Poly(NiChl-Deoxo) and Poly(NiChl-CN)) in the present invention achieve a significant improvement in photoelectric conversion efficiency, reaching 21.8%.

[0087] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A perovskite solar cell with an efficient hole transport layer without a nickel-doped chlorophyll derivative, comprising, from bottom to top: Transparent conductive glass anode, hole transport layer, perovskite layer, electron transport layer, hole blocking layer and metal cathode; Characterized in that the hole transport layer is a polymerized chlorophyll film Poly(NiChl-Deoxo) or Poly(NiChl-CN); The structural formulas of chlorophyll monomers NiChl-Deoxo and NiChl-CN are as follows:

2. The perovskite solar cell according to claim 1, characterized in that The hole transport layer is a polymerized chlorophyll film Poly (NiChl-Deoxo) or Poly (NiChl-CN) prepared by electrochemical polymerization.

3. The perovskite solar cell according to claim 1, wherein The transparent conductive glass anode is made of indium tin oxide (ITO) material, and the perovskite layer is made of Cs 0.05 FA 0.85 MA 0.1 PbI3, the electron transport layer is C 60 , the hole blocking layer is bathocuproine (BCP) and the metal cathode is silver (Ag).

4. The perovskite solar cell according to claim 1, wherein The thickness of the hole transport layer is 8-12 nm, the thickness of the perovskite layer is 540-560 nm, the thickness of the electron transport layer is 20-25 nm, the thickness of the hole blocking layer is 6-8 nm, and the thickness of the metal cathode is 50-70 nm.

5. A method for preparing a perovskite solar cell according to any one of claims 1 to 4, comprising the following steps: 1) Pre-treating the transparent conductive glass anode with ultraviolet ozone; 2) preparing a hole transport layer on the transparent conductive glass; 3) Spin-coating a perovskite layer on the hole transport layer; 4) evaporating an electron transport layer, a hole blocking layer and a metal cathode on the perovskite layer; It is characterized in that the step 2) comprises the following steps: The hole transport layer is a polymerized chlorophyll film Poly (NiChl-Deoxo) or Poly (NiChl-CN) prepared by electrochemical polymerization; A chlorophyll monomer NiChl-Deoxo or NiChl-CN solution is prepared as an electrolyte, and the hole transport layer is prepared by electrochemical deposition on the transparent conductive glass substrate obtained in step 1) using a potentiodynamic method.

6. The preparation method according to claim 5, characterized in that The steps for preparing the chlorophyll monomer NiChl-Deoxo or NiChl-CN solution in step 2) are as follows: Chlorophyll monomer NiChl-Deoxo or NiChl-CN and tetrabutylammonium hexafluorophosphate are dissolved in dichloromethane to obtain a chlorophyll monomer NiChl-Deoxo or NiChl-CN solution.

7. The preparation method according to claim 6, characterized in that The mass volume ratio of the tetrabutylammonium hexafluorophosphate, chlorophyll monomer and dichloromethane is: 1 g: 8.5 mg: 25 mL.

8. The preparation method according to claim 5, characterized in that In step 2), the hole transport layer is prepared by electrochemical deposition on the transparent conductive glass substrate obtained in step 1) using a potentiodynamic method as follows: The transparent conductive glass substrate obtained in step 1) is placed in a three-electrode system as a working electrode, a platinum sheet is used as a counter electrode, an Ag / AgCl electrode is used as a reference electrode, and a chlorophyll monomer NiChl-Deoxo or NiChl-CN solution is used as an electrolyte. Cyclic voltammetry is used for electrochemical polymerization to prepare the hole transport layer.

9. The preparation method according to claim 8, characterized in that The parameters of electrochemical polymerization were set as follows: maximum potential 1.3 V, minimum potential 0 V, starting potential 0 V, and scan rate 100 mV s -1 , the number of electrochemical cycles is 25.

10. The preparation method according to claim 5, characterized in that Step 2) After the polymerization is completed, the substrate is cleaned with dichloromethane and vacuum dried for later use.

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