Hole transport layer doped with glycine derivative and method for preparing and using the same

Abstract

The application discloses a hole transport layer doped with a glycine derivative and a preparation and application method thereof. The amino group (-NH2) in the glycine salt can interact with the polar group of Me-4PACz, helping the dispersion of Me-4PACz in a solution and on a nickel oxide surface. The benzene ring contained on the selected derivative can help the electron conduction of the hole transport layer, and the halogen substituent group can change the work function of the hole transport layer, form a highest occupied molecular orbital (HOMO) energy level matched with a wide-bandgap perovskite, reduce the non-radiative recombination of a hole transport layer / perovskite interface, improve the stability of a lower interface of a perovskite active layer, and significantly improve the efficiency and stability of a wide-bandgap perovskite solar cell prepared by applying the hole transport layer material.

Description

Technical Field

[0001] This invention relates to a technology in the field of solar cells, specifically a hole transport layer doped with glycine derivatives and its preparation and application methods. Background Technology

[0002] Perovskite / silicon tandem solar cells have great development potential due to their significantly higher efficiency compared to traditional single-junction solar cells. Current research on perovskite top cells in tandem solar cells mainly focuses on top surface passivation and perovskite mass addition. However, the interface between the perovskite bottom surface and the hole transport layer has numerous defects, which, as a substrate, can affect the perovskite crystallization process. Therefore, a high-quality hole transport layer substrate is urgently needed to fabricate high-quality wide-bandgap perovskite top cells. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, this invention proposes a hole transport layer doped with glycine derivatives, along with its preparation and application methods. The amino group (-NH2) in glycine salts interacts with the polar group of [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), facilitating its dispersion in solution and on the nickel oxide surface. Furthermore, the benzene ring in the selected derivative enhances electron conduction in the hole transport layer. Simultaneously, halogen substituents alter the work function of the hole transport layer, forming the highest occupied molecular orbital (HOMO) energy level specific to the wide-bandgap perovskite, reducing nonradiative recombination at the hole transport layer / perovskite interface, and improving the stability of the interface beneath the perovskite active layer. Wide-bandgap perovskite solar cells fabricated using this hole transport layer material exhibit significantly improved efficiency and stability.

[0004] This invention is achieved through the following technical solution:

[0005] This invention relates to a method for preparing a perovskite hole transport layer material doped with glycine derivatives, which involves preparing a hole transport layer solution doped with glycine derivatives and then spin-coating it onto nickel oxide (NiO). X The substrate of hole transport layer doped with glycine derivative was obtained by annealing. Then, a wide-bandgap perovskite precursor solution was spin-coated onto it in a two-step spin-coating method and annealed to obtain a perovskite film. Finally, a back passivation solution was added and annealed to form a wide-bandgap perovskite passivation layer.

[0006] The nickel oxide is preferably spin-coated onto ITO conductive glass.

[0007] The glycine derivative is glycine hydrochloride, phenylalanine hydrochloride, chlorophenylglycine hydrochloride, bromophenylglycine hydrochloride, fluorophenylglycine hydrochloride, or a combination thereof, preferably fluorophenylglycine hydrochloride.

[0008] The doping mass ratio of the hole transport layer solution doped with glycine derivatives is 3:5-4:5.

[0009] The hole transport layer substrate doped with glycine derivatives has a thickness of 5-10 nm; the hole transport layer material solution doped with glycine derivatives is spread on nickel oxide and then spin-coated at a speed of 5000 rpm for 30 s.

[0010] The wide-bandgap perovskite precursor solution is an organic-inorganic hybrid trans-wide-bandgap perovskite material solution, preferably FA. 0.85 MA 0.1 Cs 0.05 PbI 2.01 Br 0.99 Solution.

[0011] The two-step spin coating method is as follows: the first spin coating speed is 1000 rpm and the time is 10 s; the second spin coating speed is 5000 rpm and the time is 40 s. In the 10th second of the second spin coating, 200 μL of ethyl acetate is dropped onto the substrate as an antisolvent.

[0012] The passivation solution is preferably an isopropanol solution of ethylenediamine dihydroiodide.

[0013] This invention relates to a perovskite hole transport layer material doped with glycine derivatives prepared by the above method, comprising, in sequence, an ITO conductive glass layer, a hole transport layer doped with glycine derivatives, and a wide-bandgap perovskite absorber layer.

[0014] The ITO conductive glass layer material has an average light transmittance of >85%, a sheet resistance of 15Ω / □, and a thickness of 130-180nm.

[0015] The hole transport layer has a thickness of 10-20 nm.

[0016] The thickness of the wide-bandgap perovskite passivation layer is 500-850 nm.

[0017] The present invention relates to a solar cell based on the above-mentioned perovskite hole transport layer material doped with glycine derivatives, further comprising an electron transport layer, a hole blocking layer and a metal electrode layer disposed on a wide-bandgap perovskite absorber layer.

[0018] The thickness of the electron transport layer is 20-30 nm;

[0019] The hole blocking layer has a thickness of 6-8 nm;

[0020] The thickness of the metal electrode layer is 100-150 nm.

[0021] This invention relates to a method for fabricating the aforementioned solar cell, which is obtained by sequentially fabricating an electron transport layer, a hole blocking layer, and a metal electrode layer on the surface of a wide-bandgap perovskite absorber layer.

[0022] Technical effect

[0023] This invention incorporates a glycine derivative into the perovskite hole transport layer material Me-4PACz, and obtains the hole transport layer substrate through co-deposition, resulting in a wide-bandgap perovskite solar cell with the glycine derivative-doped hole transport layer as the substrate. The carboxyl groups in the glycine derivative can combine with metal oxides such as nickel oxide to form a self-assembly function, and the -NH2 in the glycine derivative can combine with Me-4PACz to assist the dispersion of Me-4PACz in solution and on the substrate, thereby improving the surface quality of the hole transport layer and the wide-bandgap perovskite absorber layer. The glycine derivative also includes benzene rings and halogen substituents to optimize the hole transport layer structure. Compared with the prior art, the benzene ring of the glycine derivative of the present invention can play a rigid supporting role in the molecular structure, further optimize the dispersion of Me-4PACz on the substrate, improve the wettability of the perovskite precursor solution, and enhance the π-π interaction, enhance the charge transport of the hole transport layer, and increase the short-circuit current. In addition, the halogen substituents contained on the benzene ring can specifically optimize the energy level matching of the lower interface of a specific wide-bandgap perovskite, reduce non-radiative recombination at the lower interface, thereby improving the fill factor and open-circuit voltage. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 The image shows dynamic light scattering data of the hole transport layer material solutions prepared in Example 1 and Comparative Example 1 of this invention.

[0026] Figure 3 This is a side view of the contact angle of the hole transport layer substrate prepared in Embodiment 1 and Comparative Example 1 of the present invention.

[0027] Figure 4 The ultraviolet photoelectron spectra of the hole transport layer substrates prepared in Example 1 and Comparative Example 1 of this invention are shown.

[0028] Figure 5 Kelvin probe microscopy images of the hole transport layer substrates prepared in Example 1 and Comparative Example 1 of this invention.

[0029] Figure 6 The X-ray photoelectron spectra of the perovskite thin films prepared in Example 1 and Comparative Example 1 of this invention are shown.

[0030] Figure 7This is a performance comparison chart of the perovskite solar cell devices prepared in Example 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0031] Example 1

[0032] This embodiment relates to a method such as Figure 1 The method for fabricating a wide-bandgap perovskite solar cell based on a hole transport layer doped with glycine derivatives, as shown, includes:

[0033] Step 1) Clean the ITO conductive glass layer. Select ITO conductive glass with a sheet resistance of 15Ω / □, an average transmittance of >85%, and a thickness of 1.1mm as the substrate material. Clean the ITO conductive glass in an ultrasonic cleaner for 25 minutes in sequence with detergent, deionized water, acetone, isopropanol, and ethanol. After cleaning the ITO conductive glass, dry it with nitrogen and then treat it with ultraviolet ozone for 30 minutes to remove surface organic matter and obtain a clean ITO conductive glass layer.

[0034] Step 2) Spread the nickel oxide aqueous dispersion on the ITO substrate and then spin-coat it at a speed of 3000 rpm for 20 s. After spin-coating, place the substrate on a hot plate at 140°C and anneal for 15 min to obtain a nickel oxide substrate with a thickness of 15 nm.

[0035] Step 3) Prepare a hole transport layer solution doped with glycine derivatives: Dissolve 1 mg Me-4PACz and 0.6 mg fluorophenylglycine hydrochloride in isopropanol solution, heat to 70°C and stir for 30 min to obtain a hole transport layer material solution doped with glycine derivatives.

[0036] Step 4) Spread the hole transport layer material solution doped with glycine derivative on a nickel oxide substrate and then spin-coat it. The spin-coating speed is 5000 rpm and the time is 30 s. After spin-coating, the substrate is placed on a hot plate at 100°C and annealed for 15 min to obtain a hole transport layer doped with glycine derivative with a thickness of 5-10 nm.

[0037] Step 5) Prepare an organic-inorganic hybrid trans-wide bandgap perovskite material solution: Dissolve 0.8 mol formamidinium hydroiodate, 0.09 mol methylammonium iodide, 0.05 mol cesium iodide, 0.4 mol formamidinium hydrobromide, 0.045 mol methylammonium bromide, 0.025 mol cesium bromide, 0.94 mol lead iodide, and 0.46 mol lead bromide in a DMF / DMSO mixed solvent to prepare FA. 0.85 MA 0.1 Cs 0.05 PbI 2.01 Br 0.99 Solution;

[0038] Step 6) 80 μL of wide-bandgap perovskite material solution was dropped onto the hole transport layer substrate and a two-step spin coating was performed: the first spin coating speed was 1000 rpm and the time was 10 s; the second spin coating speed was 5000 rpm and the time was 40 s. During the 10th second of the second spin coating, 200 μL of ethyl acetate was dropped onto the substrate as an antisolvent. After spin coating, the substrate was placed on a hot plate at 120 °C and annealed for 20 min to obtain a perovskite film with a thickness of 650 nm.

[0039] Step 7) Dissolve ethylenediamine dihydroiodide powder in isopropanol solution to obtain a back passivation solution with a concentration of 1 mg / ml. Drop 60 μL of the back passivation solution onto the perovskite film prepared in step 6), spin coat at 5000 rpm for 30 s, and then immediately anneal at 70 °C for 10 min to form a wide-bandgap perovskite passivation layer.

[0040] Step 8) Dissolve PCBM powder in chlorobenzene solution to obtain an electron transport layer solution with a concentration of 20 mg / ml. Drop 80 μL of the electron transport layer solution onto the film prepared in step 7), spin coat at 1500 rpm for 30 s, and then immediately anneal at 70 °C for 10 min to form a wide-bandgap perovskite electron transport layer.

[0041] Step 9) Dissolve BCP powder in isopropanol solution to obtain a hole blocking layer solution with a concentration of 0.5 mg / ml. Drop 60 μL of hole blocking layer solution onto the film prepared in step 8), spin coat at 5000 rpm for 30 s, and then immediately anneal at 70 °C for 5 min to form a wide-bandgap perovskite hole blocking layer.

[0042] Step 10) Place the film obtained in step 9) in a strong thermal evaporation environment at 2×10⁻⁶. -4 By evaporating 120nm of silver under high vacuum as a metal electrode layer, a wide-bandgap perovskite solar cell based on a hole transport layer doped with glycine derivatives is fabricated.

[0043] Comparative Example 1

[0044] The difference between this comparative example and Example 1 is that fluorophenylglycine hydrochloride is not doped. Specifically, the hole transport layer material solution prepared in step 3) of Example 1 is no longer doped with fluorophenylglycine hydrochloride powder. The hole transport layer is prepared by directly dropping Me-4PACz solution onto a nickel oxide substrate. The remaining steps are the same as in Example 1, and the wide-bandgap perovskite solar cell of this comparative example is obtained.

[0045] The properties of the products prepared in each embodiment were tested using the following methods:

[0046] Power conversion efficiency: at 100mW cm -2Under AM 1.5G solar simulator illumination (IVS-KA6000, Enlitech), using a Keithley 2400 source meter, the measured light intensity was calibrated using a standard silicon solar cell; open-circuit voltage: at 100mW / cm². -2 Under AM 1.5G solar simulator irradiation (IVS-KA6000, Enlitech), the light intensity was measured using a Keithley 2400 source meter and calibrated with a standard silicon solar cell; X-ray photoelectron spectroscopy (XPS) analysis of the perovskite thin film was performed using an ESCALAB QXi (Thermo Fisher Scientific).

[0047] Ultraviolet photoelectron spectroscopy (UVP) analysis: The perovskite thin film was analyzed using a photoelectron spectrometer (ESCALAB QXi, Thermo Fisher Scientific).

[0048] Dynamic light scattering test: The hole transport layer material solution was subjected to dynamic light scattering test using a nano-particle Zeta potentiometer (Zetasizer Ultra).

[0049] Contact angle test: The contact angle of the hole transport layer substrate was tested using a contact angle measuring instrument (DSA100, Krüger, Germany).

[0050] Kelvin probe force microscopy test: The hole transport layer substrate was tested using a high-resolution atomic force microscope (Cypher S, Oxford Instruments, USA).

[0051] Dynamic light scattering tests were performed on the hole transport layer material solutions in Example 1 and Comparative Example 1, wherein, as Figure 2 As shown, the horizontal axis represents particle size, and the vertical axis represents the corresponding intensity. The colloidal particle size in the hole transport layer material solution of the control sample is relatively large, while the colloidal particle size in the solution doped with fluorophenylglycine hydrochloride is significantly reduced. This indicates that the aggregation behavior of Me-4PACz in the solution is suppressed after doping with fluorophenylglycine hydrochloride, reducing the formation of polymers and improving the uniformity of the hole transport layer material.

[0052] The hole transport layer material films prepared in step 4) of Example 1 and Comparative Example 1 were subjected to contact angle testing, ultraviolet photoelectron spectroscopy testing, and Kelvin probe force microscopy testing. Figure 3 As shown, in the contact angle test, a larger water contact angle represents better wettability. The water contact angle of the control sample is smaller than that of the sample doped with fluorophenylglycine hydrochloride, indicating that the surface wettability of the hole transport layer is enhanced after doping with fluorophenylglycine hydrochloride, increasing the surface polarity and making it more conducive to the growth of perovskite.

[0053] like Figure 4 As shown, ultraviolet photoelectron spectroscopy (UVP) tests were performed on the comparative example and Example 1. The cutoff edge of the UVP spectrum indicates the work function level of the sample, showing a negative correlation. The electron kinetic energy cutoff edge of the control sample is larger than that of the film doped with fluorophenylglycine hydrochloride, proving that the work function of the hole transport layer material increases after doping with fluorophenylglycine hydrochloride. For wide-bandgap perovskite materials, a larger work function reduces the interfacial energy difference between the hole transport layer material and the perovskite, reducing nonradiative recombination caused by energy level mismatch.

[0054] like Figure 5 As shown, Kelvin probe force microscopy was performed on the hole transport layer substrates of the comparative example and Example 1. The average surface potential of the hole transport layer material decreased after doping with fluorophenylglycine hydrochloride, which represents an increase in the surface work function. This corroborates the results of ultraviolet photoelectron spectroscopy, proving that the hole transport layer material doped with fluorophenylglycine hydrochloride has a more matched highest occupied molecular orbital (HOMO) energy level.

[0055] The wide-bandgap perovskite thin films and corresponding solar cell devices prepared in Example 1 and Comparative Example 1 were subjected to various tests, including, for example... Figure 6 As shown in the X-ray photoelectron spectroscopy of the comparative example and Example 1, the binding energy of Pb 4f in the perovskite film doped with fluorophenylglycine hydrochloride is reduced compared to the control group, indicating that Pb... 2+ The chemical environment changes, and the co-SAM molecule interacts to some extent with the undercoordinated Pb. 2+ This combination provides passivation to the lower surface of the perovskite.

[0056] like Figure 7 As shown, the wide-bandgap perovskite solar cell prepared in Example 1 has an excellent photoelectric conversion efficiency of 23.32% and an open-circuit voltage of 1.271V.

[0057] Example 2

[0058] The difference between this embodiment and Example 1 is that the doping amount of fluorophenylglycine hydrochloride relative to Me-4PACz is adjusted to 0.2 mg, while the rest of the process is the same as in Example 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0059] Example 3

[0060] The difference between this embodiment and Example 1 is that the doping amount of fluorophenylglycine hydrochloride relative to Me-4PACz is adjusted to 0.4 mg, while the rest of the process is the same as in Example 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0061] Example 4

[0062] The difference between this embodiment and Example 1 is that the doping amount of fluorophenylglycine hydrochloride relative to Me-4PACz is adjusted to 0.8 mg, while the rest of the process is the same as in Example 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0063] Example 5

[0064] The difference between this embodiment and Example 1 is that the doping amount of fluorophenylglycine hydrochloride relative to Me-4PACz is adjusted to 1.0 mg, while the rest of the process is the same as in Example 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0065] The performance of the batteries prepared in Examples 1-5 was further tested and compared with that of Example 1. The results are shown in Table 1.

[0066] Table 1. Effect of different fluorophenylglycine hydrochloride doping concentrations on device performance

[0067]

[0068] As can be seen from Table 1, the effects of adding different amounts of fluorophenylglycine hydrochloride to the hole transport layer on perovskite solar cells are significantly different. When the doping amount is too high, it may affect the basic structure of the hole transport layer and the hole transport efficiency, thereby reducing the device performance. The optimal doping amount is 0.6 mg.

[0069] Example 6

[0070] The difference between this embodiment and Embodiment 1 is that the glycine derivative doped in step 3) of Embodiment 1 is changed to glycine hydrochloride, while the rest of the process is the same as in Embodiment 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0071] Example 7

[0072] The difference between this embodiment and Embodiment 1 is that the glycine derivative doped in step 3) of Embodiment 1 is changed to phenylalanine hydrochloride, while the rest of the process is the same as in Embodiment 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0073] Example 8

[0074] The difference between this embodiment and Embodiment 1 is that the glycine derivative doped in step 3) of Embodiment 1 is changed to chlorophenylglycine hydrochloride, while the rest of the process is the same as in Embodiment 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0075] Example 9

[0076] The difference between this embodiment and Embodiment 1 is that the glycine derivative doped in step 3) of Embodiment 1 is changed to bromophenylglycine hydrochloride, while the rest of the process is the same as in Embodiment 1, to obtain the wide-bandgap perovskite solar cell of this embodiment.

[0077] The performance of the batteries prepared in Examples 6-9 was further tested and compared with that of Example 1. The results are shown in Table 2.

[0078] Table 2. Effects of different doping types on device performance

[0079]

[0080] As shown in Table 2, the type of glycine derivative has a significant impact on the technical performance. When doped with glycine hydrochloride, the device efficiency decreases significantly; when doped with phenylpropionate hydrochloride, the improvement effect is not significant; and when doped with chloro- or bromophenylglycine hydrochloride, the open-circuit voltage and fill factor of the device are both lower than those of fluorophenylglycine hydrochloride. Therefore, for FA... 0.85 MA 0.1 Cs 0.05 PbI 2.01 Br 0.99 Wide-bandgap perovskite films with fluorophenylglycine hydrochloride-doped hole transport layers exhibit excellent hole transport enhancement effects.

[0081] Compared with existing technologies, this invention reduces defects at the perovskite lower interface by optimizing the hole transport layer structure and the contact between the hole transport layer and the trans-perovskite lower interface, thereby improving the fill factor (FF) and open-circuit voltage (Voc) to a certain extent. Simultaneously, the benzene ring in the glycine derivative enhances π-π interactions, strengthens electron delocalization, and significantly increases the short-circuit current (Jsc). Furthermore, targeted halide substitution optimizes the energy level arrangement for the wide-bandgap perovskite, further improving the fill factor (FF) and open-circuit voltage (Voc). Incorporating the glycine derivative into the perovskite hole transport layer material Me-4PACz utilizes the benzene ring to provide rigid support for the molecular structure, further optimizing the dispersion of Me-4PACz on the substrate and improving the wettability of the perovskite precursor solution. In addition, the halogen substituents on the benzene ring can specifically optimize the energy level matching at the lower interface of a specific wide-bandgap perovskite, reducing non-radiative recombination at the lower interface. The resulting organic-inorganic hybrid trans-wide-bandgap perovskite solar cell exhibits significantly improved efficiency and stability.

[0082] The above-described specific implementations can be partially adjusted by those skilled in the art in different ways without departing from the principles and purpose of the present invention. The scope of protection of the present invention is defined by the claims and is not limited to the above-described specific implementations. All implementation schemes within the scope of the claims are bound by the present invention.

Claims

1. A method for preparing a perovskite hole transport layer material doped with glycine derivatives, characterized in that, A hole transport layer solution doped with glycine derivatives was prepared and then spin-coated onto nickel oxide (NiO). X The perovskite film was obtained by spin-coating a wide-bandgap perovskite precursor solution on the substrate and annealing it. Finally, a back passivation solution was added and annealed to form a wide-bandgap perovskite passivation layer. The glycine derivative is fluorophenylglycine hydrochloride; The back passivation solution is an isopropanol solution of ethylenediamine dihydroiodide.

2. The method for preparing the perovskite hole transport layer material doped with glycine derivatives according to claim 1, characterized in that, The doping mass ratio of the hole transport layer solution doped with glycine derivatives is 3:5-4:

5.

3. The method for preparing the perovskite hole transport layer material doped with glycine derivatives according to claim 1, characterized in that, The hole transport layer substrate doped with glycine derivatives has a thickness of 5-10 nm; the hole transport layer material solution doped with glycine derivatives is spread on nickel oxide and then spin-coated at a speed of 5000 rpm for 30 s.

4. The method for preparing the perovskite hole transport layer material doped with glycine derivatives according to claim 1, characterized in that, The wide-bandgap perovskite precursor solution is FA. 0.85 MA 0.1 Cs 0.05 PbI 2.01 Br 0.99 Solution.

5. The method for preparing the perovskite hole transport layer material doped with glycine derivatives according to claim 1, characterized in that, The two-step spin coating method is as follows: the first spin coating speed is 1000 rpm and the time is 10 s; the second spin coating speed is 5000 rpm and the time is 40 s. In the 10th second of the second spin coating, 200 μL of ethyl acetate is dropped onto the substrate as an antisolvent.

6. A perovskite hole transport layer material doped with glycine derivatives prepared by the method according to any one of claims 1-5, characterized in that, It consists of, in sequence, an ITO conductive glass layer, a hole transport layer doped with glycine derivatives, and a wide-bandgap perovskite absorption layer; The average light transmittance of the ITO conductive glass layer material is >85%, and the sheet resistance is [missing information]. The thickness of this layer is 130-180 nm; The hole transport layer has a thickness of 10-20 nm; The thickness of the wide-bandgap perovskite passivation layer is 500-850 nm.

7. A solar cell based on the perovskite hole transport layer material doped with glycine derivatives as described in claim 6, characterized in that, It further includes an electron transport layer, a hole blocking layer, and a metal electrode layer disposed on the wide-bandgap perovskite absorber layer; The thickness of the electron transport layer is 20-30 nm; The hole blocking layer has a thickness of 6-8 nm; The thickness of the metal electrode layer is 100-150 nm.

8. A method for preparing the solar cell of claim 7, characterized in that, The electron transport layer, hole blocking layer and metal electrode layer were sequentially prepared on the surface of the wide-bandgap perovskite absorber layer.

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