Intrinsic broadband photoluminescence(PL)of self-trapped excitons(STEs)are systematically studied in lead-free double perovskite nanocrystals(NCs).It is clarified that bandgap(direct/indirect)has important influence o...Intrinsic broadband photoluminescence(PL)of self-trapped excitons(STEs)are systematically studied in lead-free double perovskite nanocrystals(NCs).It is clarified that bandgap(direct/indirect)has important influence on the PL properties of STEs:indirect bandgap NCs exhibit strong exciton-phonon coupling which results in non-radiative STEs,while direct bandgap NCs exhibit moderate exciton-phonon coupling,inducing bright STE PL.Furthermore,by alloying K+and Li+ions in Cs2AgInCl6 NCs,the NCs exhibit broadband white-light emission.Charge-carrier dynamics study indicates that the efficient white-light emission originates from the further suppressed non-radiative processes of the STEs in the direct bandgap structure.This work may deepen the understanding of STEs and guide the design of highperformance lead-free perovskites.展开更多
基金supported by the National Natural Science Foundation of China(21533010,21525315)the National Key Research and Development Program of China(2017YFA0204800)DICP DMTO201601,DICP ZZBS201703,and the Science Challenging Program(JCKY2016212A501).
文摘Intrinsic broadband photoluminescence(PL)of self-trapped excitons(STEs)are systematically studied in lead-free double perovskite nanocrystals(NCs).It is clarified that bandgap(direct/indirect)has important influence on the PL properties of STEs:indirect bandgap NCs exhibit strong exciton-phonon coupling which results in non-radiative STEs,while direct bandgap NCs exhibit moderate exciton-phonon coupling,inducing bright STE PL.Furthermore,by alloying K+and Li+ions in Cs2AgInCl6 NCs,the NCs exhibit broadband white-light emission.Charge-carrier dynamics study indicates that the efficient white-light emission originates from the further suppressed non-radiative processes of the STEs in the direct bandgap structure.This work may deepen the understanding of STEs and guide the design of highperformance lead-free perovskites.
