All-inorganic lead-free CsSnBr_(3)is attractive for applications in solar cells due to its nontoxicity and stability,but the device performance to date has been poor.Besides the intrinsic properties,impurities induced...All-inorganic lead-free CsSnBr_(3)is attractive for applications in solar cells due to its nontoxicity and stability,but the device performance to date has been poor.Besides the intrinsic properties,impurities induced from electrodes may significantly influence the device performance.Here,we systematically studied the stability,transition energy levels,and diffusion of impurities from the most commonly used electrodes(Au,Ag,Cu,graphite,and graphene)in CsSnBr_(3)based on density functional theory calculations.Our results reveal that,whereas graphite and graphene electrodes exhibit negligible influence on CsSnBr_(3)due to the relatively high formation energies for carbon impurities in CsSnBr_(3),atoms from the metal electrodes can effectively diffuse into CsSnBr_(3)along interstice and form electrically active impurities in CsSnBr_(3).In this case,a significant amount of donor interstitial impurities,such as Agti,Cuti,and Auti,will be formed under p-type conditions,whereas the Sn-site substitutional acceptor impurities,namely Au_(Sn)^(2-),Ag_(Sn)^(2-),and Cu_(Sn)^(2-),are the dominant impurities,especially under n-type conditions.In particular,except for Auti,all these major impurities from the metal electrodes act as nonradiative recombination centers in CsSnBr_(3)and significantly degrade the device performance.Our work highlights the distinct behaviors of the electrode impurities in CsSnBr_(3)and their influence on the related devices and provides valuable information for identifying suitable electrodes for optoelectronic applications.展开更多
基金This research was undertaken with the assistance and resources from the National Computational Infrastructure(NCI Australia),an NCRIS enabled capability supported by the Australian Government.We acknowledge the support provided by the Sydney Informatics Hub at the University of Sydney in accessing these resources.This work is partially supported by the Australian Research Council(DE180100167).
文摘All-inorganic lead-free CsSnBr_(3)is attractive for applications in solar cells due to its nontoxicity and stability,but the device performance to date has been poor.Besides the intrinsic properties,impurities induced from electrodes may significantly influence the device performance.Here,we systematically studied the stability,transition energy levels,and diffusion of impurities from the most commonly used electrodes(Au,Ag,Cu,graphite,and graphene)in CsSnBr_(3)based on density functional theory calculations.Our results reveal that,whereas graphite and graphene electrodes exhibit negligible influence on CsSnBr_(3)due to the relatively high formation energies for carbon impurities in CsSnBr_(3),atoms from the metal electrodes can effectively diffuse into CsSnBr_(3)along interstice and form electrically active impurities in CsSnBr_(3).In this case,a significant amount of donor interstitial impurities,such as Agti,Cuti,and Auti,will be formed under p-type conditions,whereas the Sn-site substitutional acceptor impurities,namely Au_(Sn)^(2-),Ag_(Sn)^(2-),and Cu_(Sn)^(2-),are the dominant impurities,especially under n-type conditions.In particular,except for Auti,all these major impurities from the metal electrodes act as nonradiative recombination centers in CsSnBr_(3)and significantly degrade the device performance.Our work highlights the distinct behaviors of the electrode impurities in CsSnBr_(3)and their influence on the related devices and provides valuable information for identifying suitable electrodes for optoelectronic applications.
