【摘要】 系统研究了非铅双钙钛矿纳米晶中自缺陷态激子引起的宽带荧光现象.带隙类型（直接、间接）对自缺陷态荧光的性质有着重要的影响:间接带隙纳米晶中,其激子-声子耦合作用较强,产生了非辐射自缺陷态,而直接带隙纳米晶中的激子-声子耦合相对较弱,因此,可以发射出较强的自缺陷态荧光.此外,通过在Cs₂AgInCl₆中引入K⁺和Li⁺,纳米晶可以发射出强白光.电荷载流子动力学研究表明,导致这种高效白光发射的原因是自缺陷态激子地非辐射复合过程被进一步抑制.该研究将进一步加深对自缺陷态的理解并对设计出优异性质的非铅钙钛矿具有指导意义.更多还原

【Abstract】 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.更多还原