Manipulating the morphology of CdS/Sb_(2)S_(3) heterojunction using a Mg-doped tin oxide buffer layer for highly efficient solar cells

摘要

Antimony sulfide(Sb_(2)S_(3))is an appealing semiconductor as light absorber for solar cells due to its high absorption coefficient,appropriate band gap(~1.7 e V)and abundance of constituent elements.However,power conversion efficiency(PCE)of Sb_(2)S_(3)-based solar cells still lags much behind the theoretically predicted due to the imperfect energy level alignment at the charge transporting layer/Sb_(2)S_(3)interfaces and hence severe charge recombination.Herein,we insert a high-temperature sintered magnesium(Mg)-doped tin oxide(SnO_(2))layer between cadmium sulfide(Cd S)and fuorine doped tin oxide to form a cascaded energy level alignment and thus mitigate interfacial charge recombination.Simultaneously,the inserted Mg-doped Sn O_(2)buffer layer facilitates the growth of the neibouring Cd S film with orientation followed by Sb_(2)S_(3)film with larger grains and fewer pinholes.Consequently,the resultant Sb_(2)S_(3)solar cells with Mg-doped SnO_(2)deliver a champion PCE of 6.31%,22.8%higher than those without a buffer layer.Our work demonstrates that deliberate absorber growth as well as efficient hole blocking upon an appropriate buffer layer is viable in obtaining solution-processed Sb_(2)S_(3)solar cells with high performance.