摘要
Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.
基金
the National Natural Science Foundation of China(22065038)
the Key Project of Natural Science Foundation of Yunnan(KC10110419)
the High-Level Talents Introduction in Yunnan Province(C619300A010)
the Fund for Excellent Young Scholars of Yunnan(K264202006820)
the Program for Excellent Young Talents of Yunnan University and Major Science(C176220200)
the International Joint Research Center for Advanced Energy Materials of Yunnan Province(202003AE140001)
the Technology Project of Precious Metal Materials Genetic Engineering in Yunnan Province(No.2019Z E001-1202002AB080001)for financial support。
