In this work,grain boundary(GB)potential barrier(ΔφGB),dopant density(Pnet),and filled trap state density(PGB,trap)were manipulated at the nanoscale by exposing the fabricated perovskite films to various relative hu...In this work,grain boundary(GB)potential barrier(ΔφGB),dopant density(Pnet),and filled trap state density(PGB,trap)were manipulated at the nanoscale by exposing the fabricated perovskite films to various relative humidity(RH)environments.Spatial mapping of surface potential in the perovskite film revealed higher positive potential at GBs than inside the grains.The averageΔφGB,Pnet,and PGB,trap in the perovskite films decreased from 0%RH to 25%RH exposure,but increased when the RH increased to 35%RH and 45%RH.This clearly indicated that perovskite solar cells fabricated at 25%RH led to the lowest average GB potential,smallest dopant density,and least filled trap states density.This is consistent with the highest photovoltaic efficiency of 18.16%at 25%RH among the different relative humidities from 0%to 45%RH.展开更多
基金This work has been supported in part by NSF MRI(1428992)NASA EPSCoR(NNX15AM83A)+3 种基金U.S.-Egypt Science and Technology(S&T)Joint Fund,SDBoR R&D Program,and EDA University Center Program(ED18DEN3030025)This work is derived from the Subject Data supported in whole or part by NAS and USAID,and any opinions,findings,conclusions,or recommendations expressed in the paper are those of the authors alone,and do not necessarily reflect the views of USAID or NAS.We would like to thank Dr Brian Moore for assisting us with high performance computing facility at South Dakota State University.W.Y.acknowledges the support from International Cooperation Project of Anhui Province(1503062018)Visiting Research Scholar Project for Young/Middle Excellent Talents of Anhui Province(gxfxZD2016110)Preeminent Youth Foundation of Anhui Polytechnic University(2016JQ002).
文摘In this work,grain boundary(GB)potential barrier(ΔφGB),dopant density(Pnet),and filled trap state density(PGB,trap)were manipulated at the nanoscale by exposing the fabricated perovskite films to various relative humidity(RH)environments.Spatial mapping of surface potential in the perovskite film revealed higher positive potential at GBs than inside the grains.The averageΔφGB,Pnet,and PGB,trap in the perovskite films decreased from 0%RH to 25%RH exposure,but increased when the RH increased to 35%RH and 45%RH.This clearly indicated that perovskite solar cells fabricated at 25%RH led to the lowest average GB potential,smallest dopant density,and least filled trap states density.This is consistent with the highest photovoltaic efficiency of 18.16%at 25%RH among the different relative humidities from 0%to 45%RH.
