Doping suppresses lattice distortion of vacant quadruple perovskites to activate self-trapped excitons emission  

作　　者：Zhipeng Chen Fei Zhang Dongwen Yang Huifang Ji Xu Chen Di Wu Xinjian Li Yu Zhang Zhifeng Shi 

机构地区：[1]Key Laboratory of Materials Physics of Ministry of Education,School of Physics and Microelectronics,Zhengzhou University,Zhengzhou 450052,China [2]State Key Laboratory on Integrated Optoelectronics,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China

出　　处：《Nano Research》2024年第4期3068-3078,共11页纳米研究（英文版）

基　　金：support from the National Key R&D Program of China(No.2022YFB2803900);the National Natural Science Foundation of China(Nos.12074347,12004346,12204426,and 61935009);Science Foundation for Distinguished Young Scholars of Henan Province(No.212300410019);the Support Program for Scientific and Technological Innovation Teams of Higher Education in Henan Province(No.231RTSTHN012).

摘　　要：The vacancy-ordered quadruple perovskite Cs_(4)CdBi_(2)Cl_(12),as a newly-emerging lead-free perovskite system,has attracted great research interest due to its excellent stability and direct band gap.However,the poor luminescence performance limits its application in light-emitting diodes(LEDs)and other fields.Herein,for the first time,an Ag^(+)ion doping strategy was proposed to greatly improve the emission performance of Cs_(4)CdBi_(2)Cl_(12) synthesized by hydrothermal method.Density functional theory calculations combined with experimental results evidence that the weak orange emission from Cs_(4)CdBi_(2)Cl_(12) is attributed to the phonon scattering and energy level crossing due to the large lattice distortion under excited states.Fortunately,Ag^(+)ion doping breaks the intrinsic crystal field environment of Cs_(4)CdBi_(2)Cl_(12),suppresses the crossover between ground and excited states,and reduces the energy loss in the form of nonradiative recombination.At a critical doping amount of 0.8%,the emission intensity of Cs_(4)CdBi_(2)Cl_(12):Ag^(+)reaches the maximum,about eight times that of the pristine sample.Moreover,the doped Cs_(4)CdBi_(2)Cl_(12) still maintains excellent stability against heat,ultraviolet irradiation,and environmental oxygen/moisture.The above advantages make it possible for this material to be used as solid-state phosphors for white LEDs applications,and the Commission International de I’Eclairage color coordinates of(0.31,0.34)and high color rendering index of 90.6 were achieved.More importantly,the white LED demonstrates remarkable operation stability in air ambient,showing almost no emission decay after a long working time for 48 h.We believe that this study puts forward an effective ion-doping strategy for emission enhancement of vacancy-ordered quadruple perovskite Cs_(4)CdBi_(2)Cl_(12),highlighting its great potential as efficient emitter compatible for practical applications.

关 键 词：Cs_(4)CdBi_(2)Cl_(12) self-trapped excitons ion doping emission enhancement stability 

分 类 号：TQ132.32[化学工程—无机化工]