Preparation And Photoelectric Properties Of Cu_aAg_m1Bi_m2I_n Thin Films Of All Inorganic Double Photovoltaic Materials

Perovskite solar cells have made significant advancements since 2009,with their photovoltaic conversion efficiency rapidly rising from 3.9%to 25.7%.However,lead toxicity and stability are two important concerns that prevent perovskite solar cells from becoming widely used.Cu2Ag Bi I6 is one of the newly discovered low-cost and environmentally friendly photovoltaic materials,which has attracted great interest from the photovoltaic and optoelectronics community due to its direct band gap,high absorption coefficient and low exciton binding energy.Therefore,this paper focuses on the low temperature preparation of Cua Agm1Bim2In thin film photovoltaic materials from metal monomers as follows:（1）A gas-solid phase diffusion-induced metal redox reaction was used to prepare thin film materials with Cu_aAg₁Bi_1.6I_n/Cu I bilayer structure,and the film quality of Cu_aAg₁Bi_1.6I_n/Cu I was further optimized by precisely regulating the thickness of Cu,and thus the thickness of Cu I.The high conductivity of Cu I,as a hole transport layer,facilitates the promotion of charge separation,which in turn improves the open circuit voltage（Voc）,short circuit current density（Jsc）and fill factor（FF）in photovoltaic devices.The results show that when the Cu thickness is 90 nm,the prepared Cu_aAg₁Bi_1.6I_n film is free of heterogeneous phases,the film surface roughness is reduced,the grain size is the largest,the crystallinity is the best,and its absorption edge is at 680 nm with a band gap of 1.87 e V.The material was assembled into a FTO/c-bvzxc TiO₂/m-TiO₂/Cu_aAg₁Bi_1.6I_n film/CuI/carbon electrode photovoltaic device with a maximum photoelectric conversion efficiency of 1.04%,and in the unencapsulated state,the photoelectric conversion efficiency could reach 61%of the initial state after100 days with good stability.（2）Cu₂Ag_m1Bi_m2 By adjusting the silver/bismuth ratio,Cu₂Ag_m1Bi_m2 thin films’crystallinity and shape were enhanced.In thin films were created using a wet process utilizing metal monomers.It was demonstrated that the films created with a 2:1silver/bismuth ratio exhibited good crystallinity,a tight grain arrangement,big grain size,and a moderate film thickness,all of which were advantageous for the transport and extraction of photogenerated carriers.The efficiency and hysteresis factor of FTO/c-Ti O₂/m-Ti O₂/Cu₂Ag_m1Bi_m2 film/carbon electrode structure of solar cells are0.67%,9.84%,and the hysteresis effect is not obvious.An innovative approach for fabricating Cu_aAg_m1Bi_m2 thin film solar cells is the wet preparation of Cu₂Ag_m1Bi_m2thin films from metal monomers.This method is straightforward,inexpensive,and low-temperature reaction preparation.