Preparation And Properties Of Hybrid Lead Halide Perovskite Solar Cells

In recent years,perovskite solar cells based on organic-inorganic hybrid perovskite material CH₃NH₃PbI₃ has attracted much attention.Perovskite cells have the advantages of high efficiency,low cost,and simple fabrication.Through the introduction of different hybrid perovskite materials and improved battery structure,the perovskite solar cell efficiency reaches 22.1%.However,the low coverage,low efficiency and instability of perovskite films still limit the development of perovskite solar cel s.Perovskite crystals have a three-dimensional structure,usually expressed as ABX₃.In this paper,A is an organic cation,methylamine ion(CH₃NH₃³⁺).B is a metal cation,metallic lead ion(Pb²⁺).Lead is generally considered to be stable and efficient in solar cells.X is a halogen anion,I^-.Based on the synthetic process of CH₃NH₃PbI₃,a series of characterization and optoelectronic properties of CH₃NH₃PbI₃ are studied by one-step and two-step methods.The results are as follows:In this study,a positive perovskite solar cell is used:FTO/TiO₂/CH₃NH₃PbI₃/Spiro-OMeTAD/Ag.Starting from improving battery efficiency,by adjusting the ratio of three solutions of DMF-DMSO-GBL in one-step method,improving the coverage of the film and increasing the grain size of perovskite.The best device is 40%DMF-DMSO,showing the largest PCE of 9.01%,JSC of 20.99 mA/cm²,V_OC of 0.847 V and FF of50.7%;By adding different antisolvents in the spin-coating process,the perovskite thin films are rapidly crystallized during the spin-coating process to reduce defects of the perovskite thin films.The perovskite solar cells prepared with chlorobenzene as antisolvent exhibited the best performance.The Jsc is 21.59 mA/cm²,the Voc is 0.668 V,the FF is 0.5685 and the PCE is 9.34%;By adjusting the concentration of MAI in two-step method,cubic perovskite particles with different particle sizes are prepared,At the MAI concentration of 8 mg/ml,the Jsc is 24.544 mA/cm²,the Voc is 0.914 V,the FF is 0.525and the PCE is 11.78%.In general,through the exploration of the perovskite film,it is known that the one-step method,although simple and easy,is unstable and the film coverage is low.The two-step method can produce a large area,flat perovskite film,and the obtained battery has stable performance,which is obviously superior to the one-step method.