Study On The Environmental Stability Of Perovskite Solar Cells

In recent years,organic-inorganic hybrid perovskite solar cells have attracted widely attention due to their rapid advancement,and their photoelectric conversion efficiency has increased from 3.8%to 22.7%in recent years,and perovskite solar cells allow low-temperature solution processing,it's easy to prepare and low cost.However,commercial applications of perovskite solar cells are greatly limited because of its sensibility to the operating environment.How to improve the environmental stability of perovskite solar cell devices has become an important issue in its development.To improve the intrinsic stability of perovskite materials,FAPbI₃ was doped by introducing some cations and anions.Different doping ratios were chosen to explore the influence of mixed cation FA⁺/Cs⁺and anion Br^-/I^-on the performance of perovskite.Cs⁺can adjust the structure of perovskite and Br^-partial replacement of halogen can reduce trap states.During the preparation of perovskite films,the optimum preparation process was determined through the exploration of spin coating speed,anti-solvent,heating temperature and time.The optimal doping ratio of the perovskite in the air environment was determined to be FA_0.8Cs_0.2PbI_2.68Br_0.32.The according device achieved a 13.9%efficiency and remained 82.5%when tested in the humidity environment?60±5%RH?after 10 days,while the FAPbI₃ device degrades rapidly in a moisture-containing air environment,and almost no response after the fourth day.Based on this experiment,Pb?SCN?₂ additive was added to the precursor solution to further explore the additive's improvement on quality and stability of perovskite film.After the addition of the additives,the flatness and denseness of the film was increased,the coverage of the film was also significantly improved.The efficiency of the solar cell employing the additive-containing film was as high as 17.0%,the efficiency remains at 85.1%of initial efficiency under the moisture environment?60±5%RH?after 45 days and 61.2%of initial efficiency after 30 days of when tested in a light and humid atmosphere.The moisture and light stability of additive-containing solar cell in the air environment was significantly improved.