低温生长高质量MAPbI3钙钛矿单晶及其光电探测性能OA

Perovskite single crystals are regarded as highly promising materials for optoelectronic devices,owing to their low defect density,outstanding photovoltaic characteristics,high resistance to moisture,and effective suppression of ion migration.However,the efficiency of perovskite single crystals-based devices in applications such as photovoltaics and light-emitting diodes has remained inferior to that of polycrystalline thin-film counterparts,primarily due to limitations in material processing and crystal growth quality.To address these challenges,a low-temperature crystal growth strategy was developed using 2-methoxyethanol(2ME)as the solvent.This approach was designed to minimize thermal fluctuations during the crystallization process,thereby suppressing the formation of defect states.In addition,owing to the low boiling point of 2ME,solvent retention on the perovskite surface was significantly reduced.When compared with MAPbI3 single crystals prepared using conventional gamma-butyrolactone(GBL)solvent,the 2ME-grown crystals exhibited a 2.7-fold enhancement in photoluminescence(PL)intensity and a 1.5-fold extension of carrier lifetime.A reduction in defect state density by 16%was achieved,along with a 19%increase in the activation energy for ion migration.Furthermore,a self-powered photodetector fabricated from 2ME-derived MAPbI3 single crystals demonstrated a responsivity of 0.55 A·W-1 and a specific detectivity of 0.80×1013 Jones at 0 V bias.These values exceed those of devices based on GBL-grown crystals by factors of 1.72 and 1.59,respectively.The response speed was also markedly improved,with rise and fall times of 2.1 ms and 3.2 ms—representing a 54%and 49%enhancement over the GBL-based device(～4.6 ms rise,～6.3 ms fall).This study establishes a reliable low-temperature pathway for the production of high-quality,low-defect MAPbI3 single crystals via 2ME.The findings indicate that this method effectively enhances the optoelectronic performance and stability of perovskite single crystals,facilitating their application in advanced devices such as high-sensitivity imaging systems,optical communication modules,and quantum detection platforms.