Due to their unique photoelectric properties,nontoxic tin-based perovskites are emerging candidates for efficient near-infrared LEDs.However,the facile oxidation of Sn2+and the rapid crystallization rate of tin-based ...Due to their unique photoelectric properties,nontoxic tin-based perovskites are emerging candidates for efficient near-infrared LEDs.However,the facile oxidation of Sn2+and the rapid crystallization rate of tin-based perovskites result in suboptimal film quality,leading to inferior efficiencies of tin-based perovskite light-emitting diodes(Pero-LEDs).In this study,we investigate the influence of commonly used solvents on the quality of the CsSnI3 films.Remarkably,DMSO exhibits a stronger interaction with SnI2,forming a stable intermediate phase of SnI2·3DMSO.This intermediate effectively inhibits the oxidation of Sn2+and slows down the crystallization rate,bringing in lower defect state density and higher photoluminescence quantum yield of the pre-pared perovskite films.Consequently,the corresponding Pero-LEDs achieve a maximum external quantum efficiency(EQE)of 5.6%,among the most effi-cient near-infrared Pero-LEDs.In addition,the device processes ultra-low effi-ciency roll-off and high reproducibility.Our research underscores the crucial role of solvent-perovskite coordination in determining film quality.These find-ings offer valuable guidance for screening solvents to prepare highly efficient and stable tin-based perovskites.展开更多
基金supported by the National Key Research and Development Program of China(2022YFA1204800)National Natural Science Foundation of China(U21A2078,22179042,and 12104170)+1 种基金the Natural Science Foundation of Fujian Province(2023J06034)Scientific Research Funds and Subsidized Project for Postgraduate's Innovative Fund in Scientific Research of Huaqiao University。
文摘Due to their unique photoelectric properties,nontoxic tin-based perovskites are emerging candidates for efficient near-infrared LEDs.However,the facile oxidation of Sn2+and the rapid crystallization rate of tin-based perovskites result in suboptimal film quality,leading to inferior efficiencies of tin-based perovskite light-emitting diodes(Pero-LEDs).In this study,we investigate the influence of commonly used solvents on the quality of the CsSnI3 films.Remarkably,DMSO exhibits a stronger interaction with SnI2,forming a stable intermediate phase of SnI2·3DMSO.This intermediate effectively inhibits the oxidation of Sn2+and slows down the crystallization rate,bringing in lower defect state density and higher photoluminescence quantum yield of the pre-pared perovskite films.Consequently,the corresponding Pero-LEDs achieve a maximum external quantum efficiency(EQE)of 5.6%,among the most effi-cient near-infrared Pero-LEDs.In addition,the device processes ultra-low effi-ciency roll-off and high reproducibility.Our research underscores the crucial role of solvent-perovskite coordination in determining film quality.These find-ings offer valuable guidance for screening solvents to prepare highly efficient and stable tin-based perovskites.
