A perovskite charge transport element

Abstract

This invention relates to the field of photoelectric detection technology and discloses a perovskite charge transport element, which consists of a conductive substrate, an electron transport layer, and a perovskite photosensitive layer. The perovskite charge transport element can be used to fabricate perovskite solar cells. This invention also discloses a method for detecting the effectiveness of charge transport at the electron transport layer / perovskite photosensitive layer interface in a perovskite solar cell. By utilizing the signal intensity of probe molecules in surface Raman imaging, the effectiveness of charge transport at the electron transport layer / perovskite photosensitive layer interface in a perovskite solar cell can be rapidly detected using surface-enhanced Raman spectroscopy. This method can complete the detection without assembling a noble metal back electrode, is simple to operate, low in cost, and exhibits high sensitivity and accuracy.

Description

Technical Field

[0001] This invention relates to the field of photoelectric detection technology, and in particular to a perovskite charge transport element. Background Technology

[0002] With rapid economic development, people's demand for energy is increasing day by day. Currently, the main energy sources are non-renewable resources such as natural gas and crude oil. However, with the dwindling supply of non-renewable resources, the development of new renewable energy sources has become particularly important. Among them, solar photovoltaic is one of the most promising renewable energy solutions.

[0003] In solar photovoltaic conversion devices, the effectiveness of charge transport at the electron transport layer / photosensitive layer interface has a significant impact on the overall performance of the solar device. However, it is currently difficult to detect the effectiveness of charge transport at the electron transport layer / photosensitive layer interface in perovskite solar cells. The efficiency of perovskite solar cells can only be detected by assembling a complete solar device with a back electrode and simulating sunlight. However, the back electrode material often requires the use of precious metals, which is not only complex in preparation but also expensive.

[0004] Therefore, there is an urgent need for a new type of solar photovoltaic conversion device that not only has excellent photoelectric conversion performance, but also enables low-cost, simple-to-operate, and highly sensitive detection of the effectiveness of charge transport at the electron transport layer / photosensitive layer interface in the solar photovoltaic conversion device. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a perovskite charge transport element, the perovskite charge transport element comprising a conductive substrate, an electron transport layer disposed on the surface of the conductive substrate, and a perovskite photosensitive layer disposed on the surface of the electron transport layer;

[0006] The conductive substrate is conductive glass coated with a transparent conductive oxide; the electron transport layer includes a blocking layer and a Raman reflective layer disposed on the blocking layer; and the perovskite photosensitive layer is disposed on the Raman reflective layer.

[0007] Furthermore, the transparent conductive oxide is fluorine-doped tin oxide; the barrier layer is titanium dioxide, tin dioxide, zinc oxide, or a fullerene derivative; the Raman reflective layer is 4-mercaptopyridine; and the perovskite photosensitive layer is methylammonium lead halide.

[0008] The present invention also provides a perovskite solar cell, wherein the perovskite solar cell includes any of the perovskite charge transport elements described above.

[0009] Furthermore, the perovskite solar cell also includes a hole transport layer and / or electrodes.

[0010] The present invention also provides a method for preparing any of the perovskite charge transport elements described above, comprising:

[0011] Step 1: After coating the upper surface of the conductive substrate with a barrier layer, calcination is performed to obtain a conductive substrate with a barrier layer.

[0012] Step 2: After coating the upper surface of the barrier layer on the conductive substrate with the barrier layer obtained in Step 1 with a Raman reflection layer, heat it to obtain a conductive substrate with an electron transport layer.

[0013] Step 3: Coat the upper surface of the electron transport layer of the conductive substrate with the electron transport layer obtained in step 2 with a perovskite photosensitive layer to obtain the perovskite charge transport element.

[0014] Furthermore, in step 1, the method of coating the barrier layer specifically involves: spin-coating the barrier layer onto the surface of the conductive substrate and then calcining it to obtain a conductive substrate with the barrier layer.

[0015] In step 2, the method of coating the Raman reflection layer specifically involves placing the Raman reflection layer on the surface of the barrier layer and then heating it to obtain a conductive substrate with an electron transport layer.

[0016] In step 3, the method of coating the perovskite photosensitive layer specifically involves placing the perovskite precursor solution in the electron transport layer and then heating it to obtain the perovskite charge transport element.

[0017] Furthermore, the perovskite precursor solution is methylammonium lead halide.

[0018] Furthermore, the methylammonium lead halide is methylammonium lead iodide.

[0019] Furthermore, the method for preparing the methylammonium lead iodide is as follows: lead iodide and methylammonium iodide are mixed in a dimethylformamide solution and heated to obtain the methylammonium lead iodide.

[0020] Furthermore, the molar ratio of lead iodide to ammonium methyl iodide is 1:1.

[0021] The present invention also provides a method for detecting charge transport at the electron transport layer / perovskite photosensitive layer interface in any of the perovskite charge transport elements or perovskite solar cells, wherein the method comprises performing surface-enhanced Raman spectroscopy imaging from the surface of the conductive substrate.

[0022] Compared with existing technologies, its advantages are as follows:

[0023] This invention discloses a perovskite charge transport element, comprising a conductive substrate, an electron transport layer, and a perovskite photosensitive layer. The perovskite charge transport element can be used to fabricate perovskite solar cells. This invention also discloses a method for detecting the effectiveness of charge transport at the electron transport layer / perovskite photosensitive layer interface in perovskite solar cells. By utilizing the signal intensity of probe molecules in surface-enhanced Raman imaging, the effectiveness of charge transport at the electron transport layer / perovskite photosensitive layer interface in perovskite solar cells can be rapidly detected. This method can complete the detection without assembling a noble metal back electrode, is simple to operate, low in cost, and exhibits high sensitivity and accuracy. Attached Figure Description

[0024] Figure 1 This is one of the surface-enhanced Raman images of 4-mercaptopyridine molecules at the electron transport layer / photosensitive layer interface prepared by perovskite precursor solutions with different proportions in Example 1 of the present invention, wherein 1) corresponds to Example 1, 2) corresponds to Example 2, 3) corresponds to Example 3, and 4) corresponds to Example 4.

[0025] Figure 2 This is the second surface-enhanced Raman imaging image of 4-mercaptopyridine molecules at the electron transport layer / photosensitive layer interface prepared by perovskite precursor solutions with different proportions in Example 1 of the present invention, wherein 1) corresponds to Example 1, 2) corresponds to Example 2, 3) corresponds to Example 3, and 4) corresponds to Example 4.

[0026] Figure 3 These are the I-V characteristic curves of batteries prepared with perovskite precursor solutions of different proportions in Example 1 of the present invention after assembling the back electrode, wherein 1) corresponds to Example 1, 2) corresponds to Example 2, 3) corresponds to Example 3, and 4) corresponds to Example 4.

[0027] Figure 4 This is a comparison chart of the efficiency of perovskite solar cells prepared in Example 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The following embodiments use FTO conductive glass.

[0030] Example 1

[0031] Step 1: The conductive substrate is ultrasonically cleaned in toluene, acetone, ethanol and deionized water, and then treated with ultraviolet light for 30 minutes; specifically, the conductive substrate in this embodiment is FTO conductive glass.

[0032] Step 2: After spin-coating the barrier layer onto the upper surface of the conductive substrate treated in Step 1, calcine it in a muffle furnace at 500°C for 30 minutes to obtain a conductive substrate with a barrier layer; specifically, the barrier layer material in this embodiment is TiO2.

[0033] Step 3: After coating the upper surface of the barrier layer on the conductive substrate with the barrier layer obtained in Step 2 with a Raman reflective layer, heat it at 100°C for 15 minutes to obtain the conductive substrate with the electron transport layer; specifically, in this embodiment, the Raman reflective layer material is 10 －3 A mol / L solution of 4-mercaptopyridine;

[0034] Step 4: Spin-coat the upper surface of the electron transport layer on the conductive substrate with the electron transport layer obtained in Step 2 with a perovskite precursor solution. Specifically, spin-coat at 1500 rpm / min for 30 seconds, then spin-coat at 3000 rpm / min for 30 seconds; then heat at 90°C for 5 minutes to evaporate the solvent and form a black perovskite photosensitive layer to obtain a perovskite charge transport element. Specifically, the preparation method of the perovskite precursor solution in this embodiment is as follows: mix 159 mg of lead iodide and 461 mg of methyl ammonium iodide at a molar ratio of 1.7:1 in 1 mL of dimethylformamide solution, and stir at 60°C for 12 hours.

[0035] Step 5: Spin-coat the surface of the perovskite photosensitive layer obtained in Step 3 with a spiro-OMeTAD solution as a hole transport layer. The solution is prepared as follows: dissolve 72.3 mg of spiro-OMeTAD in 1 ml of anhydrous chlorobenzene, then add 28.8 μl of tetra-tert-butylpyridine and 17.5 μl of acetonitrile solution with a concentration of 520 mg / ml Li-TFSI. Gently shake until spiro-OMeTAD is completely dissolved. Use a pipette to add an appropriate amount of the mixed solution onto the prepared perovskite film. Spin-coat at 1000 rpm / min for 10 seconds, then at 3000 rpm / min for 30 seconds. Deposit an Au electrode using an evaporation deposition apparatus.

[0036] Example 2

[0037] Step 1: The conductive substrate is ultrasonically cleaned in toluene, acetone, ethanol and deionized water, and then treated with ultraviolet light for 30 minutes; specifically, the conductive substrate in this embodiment is FTO conductive glass.

[0038] Step 2: After spin-coating the barrier layer onto the upper surface of the conductive substrate treated in Step 1, calcine it in a muffle furnace at 450°C for 30 minutes to obtain a conductive substrate with a barrier layer; specifically, the barrier layer material in this embodiment is TiO2.

[0039] Step 3: After coating the upper surface of the barrier layer on the conductive substrate with the barrier layer obtained in Step 2 with a Raman reflective layer, heat it at 80°C for 15 minutes to obtain a conductive substrate with an electron transport layer; specifically, in this embodiment, the Raman reflective layer material is 10 －3 A mol / L solution of 4-mercaptopyridine;

[0040] Step 4: Spin-coat the upper surface of the electron transport layer on the conductive substrate with the electron transport layer obtained in Step 2 with a perovskite precursor solution. Specifically, spin-coat at 1500 rpm / min for 30 seconds, then spin-coat at 2500 rpm / min for 30 seconds; then heat at 90°C for 5 minutes to evaporate the solvent and form a black perovskite photosensitive layer to obtain a perovskite charge transport element. Specifically, the preparation method of the perovskite precursor solution in this embodiment is as follows: mix 159 mg of lead iodide and 461 mg of methyl ammonium iodide at a molar ratio of 1.05:1 in 1 mL of dimethylformamide solution, and stir at 70°C for 12 hours.

[0041] Step 5: Spin-coat the surface of the perovskite photosensitive layer obtained in Step 3 with a spiro-OMeTAD solution as a hole transport layer. The solution is prepared as follows: dissolve 72.3 mg of spiro-OMeTAD in 1 ml of anhydrous chlorobenzene, then add 28.8 μl of tetra-tert-butylpyridine and 17.5 μl of acetonitrile solution with a concentration of 520 mg / ml Li-TFSI. Gently shake until spiro-OMeTAD is completely dissolved. Use a pipette to add an appropriate amount of the mixed solution onto the prepared perovskite film. Spin-coat at 1000 rpm / min for 10 seconds, then at 3000 rpm / min for 30 seconds. Deposit an Au electrode using an evaporation deposition apparatus.

[0042] Example 3

[0043] Step 1: The conductive substrate is ultrasonically cleaned in toluene, acetone, ethanol and deionized water, and then treated with ultraviolet light for 30 minutes; specifically, the conductive substrate in this embodiment is FTO conductive glass.

[0044] Step 2: After spin-coating the barrier layer onto the upper surface of the conductive substrate treated in Step 1, calcine it in a muffle furnace at 475°C for 30 minutes to obtain a conductive substrate with a barrier layer; specifically, the barrier layer material in this embodiment is TiO2.

[0045] Step 3: After coating the upper surface of the barrier layer on the conductive substrate with the barrier layer obtained in Step 2 with a Raman reflective layer, heat it at 90°C for 15 minutes to obtain the conductive substrate with the electron transport layer; specifically, in this embodiment, the Raman reflective layer material is 10 －3 A mol / L solution of 4-mercaptopyridine;

[0046] Step 4: Spin-coat the upper surface of the electron transport layer on the conductive substrate with the electron transport layer obtained in Step 2 with a perovskite precursor solution. Specifically, spin-coat at 1500 rpm / min for 30 seconds, then spin-coat at 2800 rpm / min for 30 seconds; then heat at 90°C for 5 minutes to evaporate the solvent and form a black perovskite photosensitive layer to obtain a perovskite charge transport element. Specifically, the preparation method of the perovskite precursor solution in this embodiment is as follows: mix 159 mg of lead iodide and 461 mg of methyl ammonium iodide in a molar ratio of 1:1 in 1 mL of dimethylformamide solution, and stir at 65°C for 12 hours.

[0047] Step 5: Spin-coat the surface of the perovskite photosensitive layer obtained in Step 3 with a spiro-OMeTAD solution as a hole transport layer. The solution is prepared as follows: dissolve 72.3 mg of spiro-OMeTAD in 1 ml of anhydrous chlorobenzene, then add 28.8 μl of tetra-tert-butylpyridine and 17.5 μl of acetonitrile solution with a concentration of 520 mg / ml Li-TFSI. Gently shake until spiro-OMeTAD is completely dissolved. Use a pipette to add an appropriate amount of the mixed solution onto the prepared perovskite film. Spin-coat at 1000 rpm / min for 10 seconds, then at 3000 rpm / min for 30 seconds. Deposit an Au electrode using an evaporation deposition apparatus.

[0048] Example 4

[0049] Step 1: The conductive substrate is ultrasonically cleaned in toluene, acetone, ethanol and deionized water, and then treated with ultraviolet light for 30 minutes; specifically, the conductive substrate in this embodiment is FTO conductive glass.

[0050] Step 2: After spin-coating the barrier layer onto the upper surface of the conductive substrate treated in Step 1, calcine it in a muffle furnace at 490°C for 30 minutes to obtain a conductive substrate with a barrier layer; specifically, the barrier layer material in this embodiment is TiO2.

[0051] Step 3: After coating the upper surface of the barrier layer on the conductive substrate with the barrier layer obtained in Step 2 with a Raman reflective layer, heat it at 95°C for 15 minutes to obtain a conductive substrate with an electron transport layer; specifically, in this embodiment, the Raman reflective layer material is 10... －3 A mol / L solution of 4-mercaptopyridine;

[0052] Step 4: Spin-coat the upper surface of the electron transport layer on the conductive substrate with the electron transport layer obtained in Step 2 with a perovskite precursor solution. Specifically, spin-coat at 1500 rpm / min for 30 seconds, then spin-coat at 3000 rpm / min for 30 seconds; then heat at 90°C for 5 minutes to evaporate the solvent and form a black perovskite photosensitive layer to obtain a perovskite charge transport element. Specifically, the preparation method of the perovskite precursor solution in this embodiment is as follows: mix 159 mg of lead iodide and 461 mg of methyl ammonium iodide at a molar ratio of 0.65:1 in 1 mL of dimethylformamide solution, and stir at 68°C for 12 hours.

[0053] Step 5: Spin-coat the surface of the perovskite photosensitive layer obtained in Step 3 with a spiro-OMeTAD solution as a hole transport layer. The solution is prepared as follows: dissolve 72.3 mg of spiro-OMeTAD in 1 ml of anhydrous chlorobenzene, then add 28.8 μl of tetra-tert-butylpyridine and 17.5 μl of acetonitrile solution with a concentration of 520 mg / ml Li-TFSI. Gently shake until spiro-OMeTAD is completely dissolved. Use a pipette to add an appropriate amount of the mixed solution onto the prepared perovskite film. Spin-coat at 1000 rpm / min for 10 seconds, then at 3000 rpm / min for 30 seconds. Deposit an Au electrode using an evaporation deposition apparatus.

[0054] Experimental Example 1

[0055] Surface-enhanced Raman spectroscopy imaging was performed on the FTO conductive glass side of the perovskite solar cells prepared in Examples 1-4. The results are shown in the figure. Figure 1 -3, Figure 1 -3, 1)-4) correspond to Examples 1-4 respectively. Higher SERS image brightness indicates higher battery charge transfer effectiveness and efficiency; therefore, Figure 1 The peak value is strongest in the mapping image of -2(2), corresponding to Figure 3 2) The highest photoelectric conversion efficiency.

[0056] Comparative Example 1

[0057] The specific preparation method is the same as in Example 1, except that step 3 is not performed, that is, the coating of the Raman reflective layer 4-mercaptopyridine molecules is not performed.

[0058] The cell efficiency of the perovskite solar cells of Example 1 and Comparative Example 1 was compared, and the results are as follows: Figure 4As shown, the results indicate that this method introduces Raman probe molecules during the assembly of perovskite solar cells. By using surface Raman imaging, the effectiveness of charge transport at the interface between the electron transport layer and the perovskite photosensitive layer in perovskite solar cells can be rapidly detected. At the same time, the introduction of probe molecules hinders electron-hole recombination, thereby enhancing the cell efficiency.

[0059] In summary, this invention provides a perovskite charge transport element composed of a conductive substrate, an electron transport layer, and a perovskite photosensitive layer, which can be used to fabricate perovskite solar cells. The perovskite charge transport element provided by this invention utilizes the intensity of probe molecular signals in surface Raman imaging to rapidly detect the effectiveness of charge transport at the electron transport layer / perovskite photosensitive layer interface in perovskite solar cells using surface-enhanced Raman spectroscopy. This method eliminates the need for assembling a noble metal back electrode, making it simple to operate and low in cost. Figure 1 -2 is a surface-enhanced Raman image of 4-mercaptopyridine molecules at the electron transport layer / photosensitive layer interface prepared by perovskite precursor solutions with different proportions in Example 1 of this invention. Figure 3 These are the I-V characteristic curves of batteries prepared with perovskite precursor solutions of different proportions and assembled with back electrodes in Example 1 of this invention. Figure 1 The scale bar in -2 shows that the lighter-colored areas indicate a stronger surface-enhanced Raman effect, representing a stronger charge transport efficiency at the electron transport layer / perovskite photosensitive layer interface. Figure 3 The relatively high battery efficiency in the present invention demonstrates that the charge transport detection method of the present invention is highly sensitive and accurate.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The solutions disclosed in the embodiments are described simply because they correspond to the methods disclosed in the embodiments; relevant parts can be found in the method section.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A perovskite charge transport element, characterized by, The perovskite charge transport element comprises a conductive substrate, an electron transport layer arranged on the surface of the conductive substrate, and a perovskite photosensitive layer arranged on the surface of the electron transport layer. The conductive substrate is a conductive glass coated with a transparent conductive oxide; the electron transport layer comprises a barrier layer and a Raman reflection layer arranged on the barrier layer; the perovskite photosensitive layer is arranged on the Raman reflection layer. The transparent conductive oxide is fluorine-doped tin oxide; the barrier layer is titanium dioxide, tin dioxide, zinc oxide or a fullerene derivative; the Raman reflection layer is 4-mercaptopyridine; and the perovskite photosensitive layer is methylammonium lead halide.

2. A perovskite solar cell, characterized by, The perovskite solar cell comprises the perovskite charge transport element of claim 1.

3. The perovskite solar cell according to claim 2, characterized in that, The perovskite solar cell further comprises a hole transport layer and / or an electrode.

4. A method for producing the perovskite charge transport element according to claim 1, characterized by, The method comprises: Step 1: calcining after coating a barrier layer on the upper surface of the conductive substrate to obtain a conductive substrate provided with a barrier layer; Step 2: heating after coating a Raman reflection layer on the upper surface of the barrier layer of the conductive substrate provided with a barrier layer obtained in step 1 to obtain a conductive substrate provided with an electron transport layer; Step 3: coating a perovskite photosensitive layer on the upper surface of the electron transport layer of the conductive substrate provided with an electron transport layer obtained in step 2 to obtain the perovskite charge transport element.

5. The production method according to claim 4, characterized by, In the step 1, the method of coating the barrier layer specifically comprises: spin-coating the barrier layer on the surface of the conductive substrate and then calcining to obtain a conductive substrate provided with a barrier layer; In the step 2, the method of coating the Raman reflection layer specifically comprises: placing the Raman reflection layer on the surface of the barrier layer and then heating to obtain a conductive substrate provided with an electron transport layer; In the step 3, the method of coating the perovskite photosensitive layer specifically comprises: placing a perovskite precursor solution on the electron transport layer and then heating to obtain the perovskite charge transport element.

6. The preparation method according to claim 5, characterized in that, The perovskite precursor solution is methylammonium lead halide.

7. The preparation method according to claim 6, characterized in that, The methylammonium lead halide is methylammonium lead iodide.

8. The preparation method according to claim 7, characterized in that, The preparation method of the methylammonium lead iodide comprises: mixing lead iodide and methylammonium iodide in a dimethylformamide solution, and then heating to obtain the methylammonium lead iodide.

9. A method for detecting the charge transport at the interface between the electron transport layer and the perovskite photoactive layer in the perovskite charge transport element of claim 1 or the perovskite solar cell of any one of claims 2-3, characterized in that, The method is: performing surface-enhanced Raman spectroscopy imaging from the surface of the conductive substrate.

Images