Green Anti-solvent Processed Highly Efficient And Non-hysteresis Perovskite Solar Cell

Hybrid organic-inorganic perovskites?HOIPs?have emerged as a promising candidate for photovoltaic?PV?application owing to their high absorption coefficient,suitable band gap?Eg?,long and balanced charge diffusion length,and robust fabrication process etc.A certified efficiency as high as 25.2%for perovskite solar cell?PSC?has been achieved,which shows great promise for next-generation photovoltaic devices.However,there are still many obstacles on its path from laboratory development stage towards commercial applications.Firstly,the most widely used method for perovskite film depositon,anti-solvant assisted crystallization,using toluene,chlorobenzene?CB?and dichloromethane?DCM?as anti-solvant hingder the future application in commercialization of perovskite-based optoelectronics.Secondly,the J-V hysteresis behavior makes it difficult to evaluate the correct efficiency and maximal power point for practical use.Finally,the stability of PSCs is still an inevitable problem in industrial application.In this work,efforts are made to solve the problems mentioned abrove.1.We report highly efficient planar perovskite solar cells?PSCs?prepared through methoxybenzene?PhOMe?green anti-solvent,reaching a power conversion efficiency?PCE?of 19.42%,which is better than CB processed PSCs?19.09%?.Compared to CB processed perovskite films,perovskites prepared by PhOMe?denoted as CB-P and PhOMe-P respectively?have a smoother surface and larger grains,with similar crystallization and absorption features.Less grain boundaries in PhOMe-P-processed perovskites can reduce charge trap states in the film and decrease the carrier recombination rates,which are beneficial for improving the performance of PSCs.2.Based on the successful case above,we apply PhOMe for the first time in the preparation of flexible perovskite solar cells,and achieve a power conversion efficiency of 17.09%.3.We obtain electron transport layer with trended changed W_f,and further use them as an ideal model to investigate the impact of W_f on the performance of PSCs.On the other hand,better band alignment between Nb:TiO₂/perovskite benefited from W_f tuning provides fast charge transfer,thereby suppressing the hysteresis of PSCs,and pushing the PCE to much higher value?21.38%?at the same time.4.We report a low temperature solution route to prepare Nb₂O₅ nano-particles,and further utilize them as ETL to fabricate PSCs with PhOMe.The PSC fabricated with Nb₂O₅ compact layer showed PCE of 20.22%?stabilized PCE of 20.14%?with V_OC of 1.19 V.Moreover,these devices exhibited improved UV stability,retaining 93%of the initial short circuit current density?Jsc?under 365 nm UV light exposure?46mW/cm²?for 10 h.