Perovskite solar cell and preparation method thereof

Abstract

The invention discloses a perovskite solar cell and a preparation method thereof, and belongs to the technical field of perovskite solar cells. The perovskite solar cell comprises conductive glass, a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer, a modification layer and an electrode layer which are arranged in sequence. And the hole transport layer comprises DLCH modified nickel oxide. The stability and the energy conversion efficiency of the perovskite solar cell are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and particularly relates to a perovskite solar cell and a preparation method thereof. Background Art

[0002] Compared with the conventional structure (n-i-p) perovskite solar cells (PSCs), the inverted structure (p-i-n) PSCs have the advantages of simple preparation process and high stability. At the same time, they can be used as the top cell of high-efficiency tandem cells, showing great commercial potential.

[0003] Nickel oxide (NiO x ) as an inorganic p-type semiconductor is commonly used as the hole transport layer (HTL) in inverted perovskite solar cells (PSCs). Due to its low cost, high transmittance, stable chemical properties and easy large-area preparation, it has received extensive attention and application. However, it has some defects that limit the energy conversion efficiency of PSCs. Even though the perovskite material itself has a relatively high defect tolerance, there are a large number of defects at the interface between untreated NiO x and the perovskite, which thus limits the photovoltaic performance of NiO x -based perovskite solar cells. Summary of the Invention

[0004] Therefore, the present invention provides a perovskite solar cell and a preparation method thereof, which uses DL-cysteine hydrochloride (DLCH)-modified nickel oxide nanoparticles as the hole transport layer, improving the stability and energy conversion efficiency of the perovskite solar cell.

[0005] To this end, the present invention provides the following technical solutions:

[0006] In a first aspect, the present application provides a perovskite solar cell, comprising a conductive glass, a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer, a modification layer and an electrode layer arranged in sequence;

[0007] The hole transport layer comprises DLCH-modified nickel oxide.

[0008] In a possible implementation manner, the perovskite layer comprises ABX 3 perovskite crystals;

[0009] A comprises one or more of Cs + , MA + and FA + ;

[0010] B comprises one or more of Pb 2+ and Sn 2+ ;

[0011] X comprises F- , Cl - , Br - and I - or more of them;

[0012] In a possible embodiment, the passivation layer includes one or more of polyetheramine, styrylamine cation derivative, and terpyridine;

[0013] In a possible embodiment, the electron transport layer includes one or more of PCBM and C60;

[0014] In a possible embodiment, the electrode layer includes one or more of silver, Cu, and Au;

[0015] In a possible embodiment, the modification layer includes one or more of BCP and SnO 2 or more of them.

[0016] In a possible embodiment, the thickness of the electron transport layer is 10 - 30 nm;

[0017] In a possible embodiment, the thickness of the modification layer is 2 - 30 nm;

[0018] In a possible embodiment, the thickness of the electrode layer is 80 - 120 nm.

[0019] The thickness of the hole transport layer can be but is not limited to 5 - 30 nm;

[0020] The thickness of the perovskite layer can be but is not limited to 400 - 800 nm;

[0021] The thickness of the passivation layer can be but is not limited to 1 - 10 nm;

[0022] Second, this application provides a preparation method of a perovskite solar cell, including the following steps:

[0023] Step 1, prepare a hole transport layer on a conductive glass using DLCH - modified nickel oxide nanoparticles;

[0024] Step 2, prepare a perovskite layer on the hole transport layer;

[0025] Step 3, prepare a passivation layer on the perovskite layer;

[0026] Step 4, prepare an electron transport layer on the passivation layer;

[0027] Step 5, prepare a modification layer on the electron transport layer;

[0028] Step 6, prepare an electrode layer on the modification layer.

[0029] In a possible implementation, the method for preparing the DLCH-modified nickel oxide nanoparticles includes:

[0030] Mix nickel oxide nanoparticles, DLCH, and a solvent, stir, perform solid-liquid separation, and dry the separated solid.

[0031] In a possible implementation, the step of mixing nickel oxide nanoparticles, DLCH, and a solvent and stirring includes:

[0032] Disperse the nickel oxide nanoparticles in a first solvent to obtain a nickel oxide dispersion;

[0033] Dissolve DLCH in a second solvent to obtain a DLCH solution;

[0034] Mix and stir the nickel oxide dispersion and the DLCH solution.

[0035] In a possible implementation, the concentration of the nickel oxide dispersion is 5 - 20 mg / mL;

[0036] In a possible implementation, the concentration of the DLCH solution is 0.5 - 2 mg / mL;

[0037] In a possible implementation, the nickel oxide dispersion and the DLCH solution are mixed in a volume ratio of (1 - 2):1. Exemplarily, it can be 1:1;

[0038] In a possible implementation, the first solvent and / or the second solvent includes water;

[0039] In a possible implementation, the stirring time is 4 - 8 h.

[0040] In a possible implementation, the solid-liquid separation is centrifugal separation;

[0041] Optionally, the centrifugation speed is 2000 - 5000 rpm / s, and the centrifugation time is 3 - 10 min;

[0042] In a possible implementation, the drying temperature is 45 - 80 °C, and the drying time is 4 - 8 h.

[0043] In a possible implementation, step 1 includes:

[0044] Disperse the DLCH-modified nickel oxide nanoparticles in a third solvent to obtain a modified nickel oxide dispersion;

[0045] The modified nickel oxide dispersion is coated on the conductive glass by spin coating and annealed at a temperature in the range of 100-200 °C for 10-20 min; the spin coating speed is 1000-2000 rpm / s and the spin coating time is 20-60 s;

[0046] Optionally, the third solvent includes water.

[0047] Before preparing the hole transport layer, the conductive glass is pretreated: the conductive glass is cleaned and dried, and subjected to ultraviolet ozone treatment before use.

[0048] In a possible implementation, the electron transport layer is PCBM ([6,6]-phenyl-C61-butyric acid isomethyl ester). PCBM is dissolved in a chlorobenzene solution to prepare a PCBM chlorobenzene solution with a concentration of 10-30 mg / mL. Exemplarily, the concentration can be 20 mg / mL. The PCBM chlorobenzene solution is spin-coated on the perovskite layer by spin coating to obtain the electron transport layer, where the spin coating speed is 1000-2000 rpm / s, the spin coating time is 40-60 s, the annealing temperature is 80-120 °C, and the annealing time is 5-10 min.

[0049] In a possible implementation, the electron transport layer is C60, and it can be vacuum thermally evaporated to a thickness of 10-30 nm.

[0050] In a possible implementation, the modification layer can be BCP (bathocuproine) and can be prepared with a thickness of 5-10 nm by vacuum evaporation;

[0051] In a possible implementation, the modification layer can be SnO 2 , and is prepared with a thickness of 10-30 nm by atomic deposition. Exemplarily, it can be 20 nm.

[0052] In a possible implementation, the electrode layer is prepared by vacuum evaporation.

[0053] The technical solution of the present invention has the following advantages:

[0054] The perovskite solar cell of the present invention includes a conductive glass, a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer, a modification layer, and an electrode layer which are arranged in sequence; the hole transport layer includes DLCH-modified nickel oxide. In the present invention, nickel oxide is modified by the chiral molecule DL-cysteine hydrochloride (DLCH). DLCH contains various functional groups, including a mercapto group, a carboxyl group, an amino group, and a chloride ion. The mercapto group can bind to nickel oxide nanoparticles, so that the surface of nickel oxide contains a large number of DLCH molecules. Other various functional groups can passivate the positive and negative charge defects of the perovskite layer and the interface through synergistic effects. In addition, the modified nickel oxide nanoparticles are more easily dispersed in water, not easily aggregated, and are more easily dispersed on the surface of the conductive glass. Due to the above advantages, the perovskite battery device of the present invention has higher efficiency and long-term stability. Description of the Drawings

[0055] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0056] Figure 1 The photoelectric conversion efficiency of the perovskite solar cells prepared in Examples 1-3 and Comparative Example 1;

[0057] Figure 2 The stability test results of the perovskite solar cells prepared in Example 2 and Comparative Example 1. Specific Embodiments

[0058] The following embodiments are provided to better further understand the present invention, and are not limited to the best embodiment. They do not limit the content and protection scope of the present invention. Any product that is the same as or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior art features falls within the protection scope of the present invention.

[0059] For those steps or conditions not specified in the examples, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments not specified by the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0060] Example 1

[0061] This example provides a preparation method of a perovskite solar cell, including the following steps:

[0062] 1. The ITO conductive glass with a size of 20*25 cm was ultrasonically cleaned successively with glass cleaning agent, deionized water, ethanol, and isopropanol, and the ultrasonic treatment time for each solution was 30 min; the ITO conductive glass was dried with dry air; subsequently, the ITO conductive glass was treated with ultraviolet-ozone for 15 min.

[0063] 2. NiOx was dispersed in deionized water to prepare a nickel oxide dispersion with a concentration of 5 mg / mL of NiOx, and DLCH was configured into a DLCH aqueous solution with a concentration of 0.5 mg / mL. The nickel oxide dispersion and the DLCH aqueous solution were mixed in a volume ratio of 1:1 and reacted under magnetic stirring for 8 h. After the reaction was completed, the solution was poured into a centrifuge tube, and the precipitation centrifugation speed was 5000 rpm / s, and the centrifugation time was 10 min. The drying temperature of the centrifuged product was 60 °C, and the drying time was 6 h to obtain DLCH-modified nickel oxide nanoparticles. The DLCH-modified nickel oxide nanoparticles were dispersed in deionized water to prepare a modified nickel oxide dispersion with a concentration of 10 mg / mL, and after ultrasonic oscillation for 30 min, it was reserved; the modified nickel oxide dispersion was dropped onto the surface of the ITO conductive glass and rotated at 2000 rpm for 30 s to obtain a NiOx liquid film; the NiOx liquid film was annealed at 150 °C for 10 min.

[0064] 3. Prepare a perovskite precursor solution with a concentration of 1.4 mM of Cs 0.05 FA 0.8 MA 0.15 PbI 2.3 Br 0.7 , and the perovskite precursor solution was coated on the hole transport layer by spin coating. The spin coating method was divided into two stages: the rotation speed in the first stage was 2000 rpm / s, and the spin coating time was 20 s; the rotation speed in the second stage was 5000 rpm / s, and the spin coating time was 10 s. 100 ul of chlorobenzene was dropped at 25 s in the first stage; after spin coating, annealing treatment was carried out; the annealing temperature was 100 °C, and the annealing time was 10 min.

[0065] 4. The passivation layer used PEAI (phenethylammonium iodide) with a concentration of 1 mg / mL. 100 ul of the PEAI solution was dropped onto the surface of the perovskite layer and rotated at 3000 rpm for 30 s, and annealed at 80 °C for 5 min.

[0066] 5. Evaporate a 20-nm-thick C60 as the hole transport layer on the passivation layer.

[0067] 6. Evaporate an 8-nm-thick BCP as a modification on the hole transport layer.

[0068] 7. Evaporate a 100-nm-thick silver electrode on the modification layer.

[0069] Example 2

[0070] This embodiment provides a method for preparing a perovskite solar cell, comprising the following steps:

[0071] 1. The ITO conductive glass with a size of 20*25 cm is ultrasonically cleaned successively with glass cleaning agent, deionized water, ethanol and isopropanol, and the ultrasonic treatment time for each solution is 30 min; the ITO conductive glass is dried with dry air; subsequently, the ITO conductive glass is treated with ultraviolet-ozone for 15 min.

[0072] 2. NiOx is dispersed in deionized water to prepare a nickel oxide dispersion with a concentration of 5 mg / mL of NiOx, DLCH is configured into a DLCH aqueous solution with a concentration of 1 mg / mL, the nickel oxide dispersion and the DLCH aqueous solution are mixed in a volume ratio of 1:1, and the reaction is carried out under magnetic stirring for 8 h. After the reaction is completed, the solution is poured into a centrifuge tube, the precipitation centrifugation speed is 5000 rpm / s, and the centrifugation time is 10 min. The drying temperature of the centrifuged product is 60 °C, and the drying time is 6 h to obtain DLCH-modified nickel oxide nanoparticles. The DLCH-modified nickel oxide nanoparticles are dispersed in deionized water to be configured into a modified nickel oxide dispersion with a concentration of 10 mg / mL, and after ultrasonic oscillation for 30 min, it is filtered and reserved; the modified nickel oxide dispersion is dropped on the surface of the ITO conductive glass and rotated at 2000 rpm for 30 s to obtain a NiOx liquid film; the NiOx liquid film is annealed at 150 °C for 10 min.

[0073] 3. Prepare a perovskite precursor solution with a concentration of 1.4 mM of Cs 0.05 FA 0.8 MA 0.15 PbI 2.3 Br 0.7 . The perovskite precursor solution is coated on the hole transport layer by spin coating. The spin coating method is divided into two stages: the rotation speed in the first stage is 2000 rpm / s, and the spin coating time is 20 s; the rotation speed in the second stage is 5000 rpm / s, and the spin coating time is 10 s. 100 μL of chlorobenzene is dropped at 25 s in the first stage; after spin coating, annealing treatment is carried out; the annealing temperature is 100 °C, and the annealing time is 10 min.

[0074] 4. The passivation layer uses PEAI with a concentration of 1 mg / mL. Take 100 μL of the PEAI solution and drop it onto the surface of the perovskite layer, rotate at 3000 rpm for 30 s, and anneal at 80 °C for 5 min.

[0075] 5. Evaporate 20 nm thick C60 on the passivation layer as the hole transport layer.

[0076] 6. Evaporate 8 nm thick BCP on the hole transport layer as a modification.

[0077] 7. Evaporate a 100 nm thick silver electrode on the modification layer.

[0078] Example 3

[0079] This example provides a method for preparing a perovskite solar cell, which includes the following steps:

[0080] 1. The ITO conductive glass with a size of 20*25 cm is ultrasonically cleaned successively with glass cleaning agent, deionized water, ethanol and isopropanol, and the ultrasonic treatment time for each solution is 30 min; the ITO conductive glass is dried with dry air; subsequently, the ITO conductive glass is treated with ultraviolet-ozone for 15 min.

[0081] 2. NiOx is dispersed in deionized water to prepare a nickel oxide dispersion with a concentration of 5 mg / mL of NiOx, DLCH is configured into a DLCH aqueous solution with a concentration of 1.5 mg / mL, the nickel oxide dispersion and the DLCH aqueous solution are mixed in a volume ratio of 1:1, and the reaction is carried out under magnetic stirring for 8 h. After the reaction is completed, the solution is poured into a centrifuge tube, the precipitation centrifugation speed is 5000 rpm / s, and the centrifugation time is 10 min. The drying temperature of the centrifuged product is 60 °C, and the drying time is 6 h to obtain DLCH-modified nickel oxide nanoparticles. The DLCH-modified nickel oxide nanoparticles are dispersed in deionized water to be configured into a modified nickel oxide dispersion with a concentration of 10 mg / mL, and after ultrasonic oscillation for 30 min, it is filtered and reserved; the modified nickel oxide dispersion is dropped on the surface of the ITO conductive glass and rotated at 2000 rpm for 30 s to obtain a NiOx liquid film; the NiOx liquid film is annealed at 150 °C for 10 min.

[0082] 3. Prepare a perovskite precursor solution with a concentration of 1.4 mM of Cs 0.05 FA 0.8 MA 0.15 PbI 2.3 Br 0.7 , and the perovskite precursor solution is coated on the hole transport layer by spin coating. The spin coating method is divided into two stages: the rotation speed in the first stage is 2000 rpm / s, and the spin coating time is 20 s; the rotation speed in the second stage is 5000 rpm / s, and the spin coating time is 10 s. 100 μL of chlorobenzene is dropped at 25 s in the first stage; after spin coating, annealing treatment is carried out; the annealing temperature is 100 °C, and the annealing time is 10 min.

[0083] 4. The passivation layer uses PEAI with a concentration of 1 mg / mL. Take 100 μL of the PEAI solution and drop it onto the surface of the perovskite layer, rotate at 3000 rpm for 30 s, and anneal at 80 °C for 5 min.

[0084] 5. Evaporate 20 nm thick C60 on the passivation layer as the hole transport layer.

[0085] 6. Evaporate BCP with a thickness of 8 nm on the hole transport layer as a modification.

[0086] 7. Evaporate a silver electrode with a thickness of 100 nm on the modification layer.

[0087] Comparative Example 1

[0088] This comparative example is basically the same as Example 1, except that in this comparative example, ordinary nickel oxide nanoparticles are used to prepare the hole transport layer, and DLCH is not used to modify nickel oxide.

[0089] Test Example

[0090] Test the photoelectric conversion efficiency (PCE) and stability of the perovskite solar cells prepared in Example 1 - Example 3 and Comparative Example 1.

[0091] Photoelectric conversion efficiency: The conversion efficiency of the battery is tested by an electrochemical workstation. Use a standard silicon solar cell calibrated by NIM to calibrate the light intensity to AM1.5G one sun (100 mW / cm 2 ). Use a metal mask to define the effective active area of the battery devices prepared in the examples and comparative examples as 0.1 cm 2 . Measure at a scanning rate of 100 mV / s in the range of 1.2 V to -0.1 V. The test results are shown in Figure 1 . Stability: The stability test is the same as the photoelectric conversion efficiency test. Take it out at intervals of one week for repeated testing. The test results are shown in Figure 2 .

[0092] It can be seen from Figure 1 and Figure 2 that both the photoelectric conversion efficiency and stability of the perovskite solar cells prepared in this application are significantly improved.

[0093] Obviously, the above embodiments are only examples clearly described, rather than limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A perovskite solar cell, characterized in that: It includes a conductive glass, a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer, a modification layer and an electrode layer arranged in sequence; The hole transport layer includes DLCH-modified nickel oxide.

2. The perovskite solar cell according to claim 1, characterized in that At least one of the following conditions is met: (1) The perovskite layer includes ABX3 perovskite crystals; A includes Cs + 、MA + and FA + One or more of; B includes Pb 2+ and Sn 2+ One or more of; X includes F - , Cl - Br - and I - One or more of; (2) The passivation layer comprises one or more of polyetheramine, phenylethylamine cationic derivatives, and terpyridine; (3) The electron transport layer includes one or more of PCBM and C60; (4) The electrode layer includes one or more of silver, Cu and Au; (5) The modified layer includes one or more of BCP and SnO2.

3. The perovskite solar cell according to claim 1 or 2, characterized in that: At least one of the following conditions is met: (1) The thickness of the electron transport layer is 10 to 30 nm; (2) The thickness of the modified layer is 2 to 30 nm; (3) The thickness of the electrode layer is 80-120 nm.

4. A method for preparing a perovskite solar cell according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1, preparing a hole transport layer on a conductive glass using DLCH-modified nickel oxide nanoparticles; Step 2, preparing a perovskite layer on the hole transport layer; Step 3, preparing a passivation layer on the perovskite layer; Step 4, preparing an electron transport layer on the passivation layer; Step 5, preparing a modification layer on the electron transport layer; Step 6: preparing an electrode layer on the modified layer.

5. The method for preparing a perovskite solar cell according to claim 4, characterized in that: The preparation method of the DLCH modified nickel oxide nanoparticles comprises: The nickel oxide nanoparticles, DLCH and a solvent are mixed and stirred, the solid and the liquid are separated, and the separated solid is dried.

6. The method for preparing a perovskite solar cell according to claim 5, characterized in that: The steps of mixing and stirring nickel oxide nanoparticles, DLCH and a solvent include: dispersing the nickel oxide nanoparticles in a first solvent to prepare a nickel oxide dispersion; dissolving DLCH in a second solvent to prepare a DLCH solution; The nickel oxide dispersion and the DLCH solution were mixed and stirred.

7. The method for preparing a perovskite solar cell according to claim 6, characterized in that: At least one of the following conditions is met: (1) The concentration of the nickel oxide dispersion is 5 to 20 mg / mL; (2) The concentration of the DLCH solution is 0.5 to 2 mg / mL; (3) mixing the nickel oxide dispersion and the DLCH solution in a volume ratio of (1-2):1; (4) the first solvent and / or the second solvent comprises water; (5) The stirring time is 4 to 8 hours.

8. The method for preparing a perovskite solar cell according to claim 5, characterized in that: At least one of the following conditions is met: (1) The solid-liquid separation is centrifugal separation; Optionally, the centrifugal speed is 2000-5000 rpm / s, and the centrifugal time is 3-10 min; (2) The drying temperature is 45 to 80° C. and the drying time is 4 to 8 hours.

9. The method for preparing a perovskite solar cell according to any one of claims 4 to 8, characterized in that: Step 1 includes: dispersing DLCH-modified nickel oxide nanoparticles in a third solvent to prepare a modified nickel oxide dispersion; The modified nickel oxide dispersion is coated on the conductive glass by spin coating, and annealed at 100-200° C. for 10-20 minutes; wherein the spin coating speed is 1000-2000 rpm / s, and the spin coating time is 20-60 seconds; Optionally, the third solvent comprises water.

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