Study On Preparation And Performance Of Perovskite Solar Cells With Copper Hole Layer

As the new darling of the 21st century,perovskite solar cells have the advantages of long carrier lifetimes,low-cost fabrication,and simple process flow.However,nowadays,the common organic hole-transporting material Spiro-OMe TAD is too complicated in the preparation process to expensive.The conductivity is low and Spiro-OMe TAD needs to be modified by doping.At the same time,the crystallization speed of the perovskite film is too fast during the preparation process.The film coverage degree is low,and the surface of the film has ravines and gullies which increases the charge load.To solve the above problems,in this paper,copper indium oxide Cu₂In₂O₅ powder was prepared by a hydrothermal method in the ethanol-water system and copper oxide CuO powder was prepared by solution method.Cu₂In₂O₅ and CuO were both used as hole transport layers.The perovskite films were modified with cellulose acetate and glutinous rice flour.The two modifiers reduced the crystallization rate and the charge recombination of the perovskite film.The two modifiers improved the perovskite film coverage.The main work was as follows.1.In this paper,the precursor powder was synthesized in the reaction vessel under the influence of ethanol-water.The source of Cu was copper acetate(CH₃COO)₂Cu,and the source of In was indium acetate(CH₃COO)₃In.The potassium hydroxide KOH was selected as the mineralizer.After annealing treatment,Cu₂In₂O₅ powder was obtained.By adjusting the different amount ratios of substances of Cu and In,the preparation of high-purity Cu₂In₂O₅ powder was achieved.XRD and TEM determined phase composition and the crystal structure of Cu₂In₂O₅ powder.SEM characterized the morphology of Cu₂In₂O₅ powder.UV-vis studied the bandgap of Cu₂In₂O₅ film.The Mott-Schottky(M-S)method calculated the carrier concentration of Cu₂In₂O₅film.Finally,the Perovskite solar cells PSCs were tested by the linear sweep voltammetry(LSV)test.When the amount of substance ratio of Cu and In was 1.3:1,the Cu₂In₂O₅ thin film was used as the hole transport layer,and it was assembled into solar cells with the best efficiency.The bandgap value was 3.77 e V,and the Cu₂In₂O₅ thin film could transmit more sunlight for absorption by the perovskite layer.The carrier concentration reached the order of?10¹⁵.The assembled solar cells had excellent electrochemical performance.2.CuO was prepared by the solution method.(CH₃COO)₂Cu was used as copper source and KOH was used as p H regulator.CuO was used as the hole transport material.The assembled solar cell was compared with that of Cu₂In₂O₅.XRD characterized the phase composition and crystal structure of CuO.UV-vis calculated the bandgap of CuO film.M-S test calculated flat band potential and carrier concentration of CuO film,respectively.Finally,it was assembled into a solar cell for LSV test.The test result showed that the bandgap of CuO was 1.56 e V.The carrier concentration was1.06·10¹³ cm^-3.3.Using cellulose acetate CA and glutinous rice flour GRF as modifiers for perovskite films,the annealed film was assembled into perovskite solar cells for LSV test.Based on the photoelectric conversion efficiency obtained by the test,a single factor optimization experiment was performed on the perovskite film.The optimal formula and conditions were CA:GRF 3%:2%,DMF:DMSO 1:1,the annealing temperature of 100?,and the annealing time of 120 min.XRD determined the crystal structure,phase composition,and grain size of the perovskite film.SEM-EDS characterized the surface morphology and element distribution of the perovskite film.FTIR and XPS tests explored the modification mechanism of the perovskite film by CA and GRF.UV-vis measured the optical bandgap of perovskite film.And the perovskite film was assembled into a solar cell for LSV testing.The test results showed that the bandgap of the modified perovskite film was 1.45 e V,and the solar cell conversion efficiency was 2.88%.