物理化学学报2022，Vol.38Issue(3)：39-46,8.DOI:10.3866/PKU.WHXB202003022
溶剂工程调控钙钛矿薄膜中PbI2和PbI2(DMSO)的形成
Controllable Formation of PbI2 and PbI2(DMSO)Nano Domains in Perovskite Films through Precursor Solvent Engineering
摘要
Abstract
Perovskite solar cells(PSCs)attract much attention for their high efficiency and low processing cost.Power conversion efficiencies(PCEs)higher than 25％have been reported in literature,demonstrating the excellent application prospect of PSCs.In general,the crystallinity and the film composition of perovskite thin films are significant factors in determining device performance.Much effort has been made to control the growth process of perovskite films through the use of additives,passivation layers,special atmosphere treatments,precursor regulation etc.Among these methods,precursor solvent engineering is a simple and direct way to control the perovskite quality,but the controllability of components through solvent engineering is still difficult and has not yet been reported.Herein,we report the controlled formation of PbI2 and PbI2 with dimethyl sulfoxide(DMSO)nano domains through precursor solvent engineering.In particular,tuning the solvent content of the dimethyl sulfoxide:1,4-butyrolactone:N,N-dimethylformamide(DMSO ∶ GBL∶ DMF)in the perovskite precursor solution,controlled the content of PbI2 and PbI2(DMSO)domains.Due to the lower boiling point and weaker coordination of DMF relative to DMSO,part of methylammonium iodide(MAI)would escape from the wet films during the evaporation process.Therefore,the PbI2(DMSO)can't completely convert to perovskite crystals and is retained in the final films as residual PbI2(DMSO)domains.Both UV-vis absorption spectrum and XRD spectrum confirmed the existence of PbI2 and PbI2(DMSO)domains.Importantly,the content of PbI2(DMSO)was controllable by simply changing the relative proportion of DMF.With an increase in the DMF content,the residual PbI2(DMSO)domains gradually increase.In addition,the influence of PbI2 and PbI2(DMSO)domains on the device performance was systematically investigated.The formation of PbI2(DMSO)domains caused a decrease in external quantum efficiency(EQE)of the device over 300-425 nm,and consequently decreased the device performance.That was because the PbI2(DMSO)domain has strong absorption over 300-425 nm.Therefore,the PbI2(DMSO)domains would absorb the photons over 300-425 nm prior to the perovskite,however the photons absorbed by the PbI2(DMSO)domains are not converted into the photocurrent.Thus,the perovskite solar cell containing PbI2(DMSO)showed an EQE loss over 300-425 nm in the EQE spectra.This work provides a simple method to control the components,especially the content of the PbI2(DMSO)domains,in perovskite films through regulating the precursor solvent.Additionally,this work revealed a PbI2(DMSO)domain related EQE loss phenomenon,highlighting the importance of controlling this component.关键词
钙钛矿太阳能电池/PbI2/PbI2(DMSO)/钙钛矿前驱体/外量子效率Key words
Perovskite solar cell/PbI2/PbI2(DMSO)/Perovskite precursor/External quantum efficiency分类
化学化工引用本文复制引用
查吴送,张连萍,文龙,康嘉晨,骆群,陈沁,杨上峰,马昌期..溶剂工程调控钙钛矿薄膜中PbI2和PbI2(DMSO)的形成[J].物理化学学报,2022,38(3):39-46,8.基金项目
The project was supported by the Natural Science Foundation of Jiangsu Province,China(BK20181197),the Natural Science Foundation of Jiangxi Province,China(20181BAB206017),the Youth Innovation Promotion Association,CAS(2019317),and the National Natural Science Foundation of China(51773224).江苏省自然科学基金(BK20181197),江西省自然科学基金(20181BAB206017),中国科学院青年创新促进会(2019317)和国家自然科学基金(51773224)资助项目 （BK20181197）
