Incorporation sodium ions into monodisperse lead-free double perovskite Cs_(2)AgBiCl_(6) nanocrystals to improve optical properties  

作　　者：Song Wang Ying Xie Wenchao Jiang Binghang Liu Keying Shi Kai Pan 

机构地区：[1]Key Laboratory of Functional Inorganic Material Chemistry,Ministry of Education,Heilongjiang University,Harbin 150080,China [2]School of Materials Science and Engineering,Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications,Changzhou University,Changzhou 213164,China [3]State Key Laboratory of Catalysis,Dalian National Laboratory for Clean Energy,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China

出　　处：《Chinese Chemical Letters》2024年第3期549-553,共5页中国化学快报（英文版）

基　　金：the support of the National Natural Science Foundation of China(No.21473051);the Natural Science Foundation of Heilongjiang Province(No.LH2019B014);Youth Science and Technology Innovation Team Project of Heilongjiang Province(No.2018-KYYWF-1593)。

摘　　要：Lead-free double perovskite nanocrystals(NCs)have emerged as a promising candidate in the optical field,owing to their non-toxic,good moist heat and chemical stability.However,their poor optical properties limited their application.To improve the optical properties of lead-free double perovskite NCs,metal ion doping or alloying had been suggested as a promising strategy.Here,we prepared monodisperse,uniformly sized,cubic morphology of Cs_(2)AgBiCl_(6)NCs with different Na^(+)incorporation amounts via a simple hot-injection method.The Na^(+)incorporation broke the parity-forbidden transition by reducing the inversion symmetry of the electron wave function at the Ag site,which changed the parity of the self-trapped exciton wave function and thus allowed radiative recombination.As a result,the photoluminescence quantum yield(PLQY)of Na^(+)-alloyed Cs_(2)AgBiCl_(6)NCs(12.1%)was higher than that of Cs_(2)AgBiCl_(6)NCs(2.4%),and the exciton lifetime of Na^(+)-alloyed Cs_(2)AgBiCl_(6)NCs increased to 36.98 ns from 17.58 ns for Cs_(2)AgBiCl_(6)NCs.By adjusting the amount of Na^(+)incorporation,the band gap of Cs_(2)AgBiCl_(6)NCs can be significantly tuned from~2.90 eV to~3.50 eV.Furthermore,the temperature-dependent photoluminescence spectra indicated that the Na^(+)-alloyed Cs_(2)AgBiCl_(6)NCs possessed higher longitudinal optical phonon energy and exciton binding energy compared to Cs_(2)AgBiCl_(6)NCs.This suggested that there were strong exciton-phonon interactions during exciton recombination,a reduced probability of non-radiative processes,and excellent thermal stability.It offers a promising strategy for improving the optical properties of lead-free double perovskite NCs,and have the potential to replace traditional lead halide perovskite NCs in future optoelectronic applications.

关 键 词：NANOCRYSTALS Alloy Double perovskites Optical properties Exciton binding energy 

分 类 号：TB383.1[一般工业技术—材料科学与工程]