摘要
Wide-bandgap(WBG)perovskites have emerged as promising materials for the construction of perovskite/silicon tandem solar cells.However,poor long-term operational stability due to the notorious photo-induced halide segregation is commonly observed.Here,we report the synthesis of stable~1.73 eV MA-based mixed I/Br WBG perovskites by ionic liquid solvent,methylammonium acetate(MAAc).The special internal hydrogen bond(N–H…I and N–H…Br)environment in the ionic liquid MAAc solvent over traditional N,N-dimethylformamide/dimethyl sulfoxide solvent stabilizes the diffusion of halide ions.This allows the suppression of the halide segregation in the mixed I/Br WBG perovskite film,which is previously suggested to be difficult.The hydrogen bonds also enable excellent decoupling of the crystal nucleation and growth process.Finally,a champion device efficiency of 20.59%is achieved,which is one of the highest reports,with improved ambient air,heat,and light stability.
基金
financially supported by the Natural Science Foundation of China(91833304 and 51972172)
Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(BK20200034)
the Young 1000 Talents Global Recruitment Program of China。
