CsFAMA混合阳离子钙钛矿的带尾态发光和热无序度分析  

Luminescence with Band-tail States and Thermal Disorder Analysis of CsFAMA Mixed Cationic Perovskite

作　　者：张贵银[1] 武晓蕊 王烨 赵晋津 党伟[3,4] ZHANG Gui-yin;WU Xiao-rui;WANG Ye;ZHAO Jin-jin;DANG Wei(Department of Mathematics and Physics,North China Electric Power University,Baoding 071003,China;School of Materials Science and Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;College of Physical Science and Technology,Hebei University,Baoding 071002,China;Hebei Provincial Center for Optical Sensing Innovation,Baoding 071002,China)

机构地区：[1]华北电力大学数理系,河北保定071003 [2]石家庄铁道大学材料科学与工程学院,河北石家庄050043 [3]河北大学物理科学与技术学院,河北保定071002 [4]河北省光学感知技术创新中心,河北保定071002

出　　处：《发光学报》2022年第12期1938-1947,共10页Chinese Journal of Luminescence

基　　金：河北省自然科学基金(F2017201136)资助项目。

摘　　要：利用稳态和瞬态光致发光光谱技术对Cs_(0.05)FA_(0.81)MA_(0.14)PbI_(2.55)Br_(0.45)(以下简称CsFAMA混合阳离子钙钛矿)薄膜的发光过程进行研究。在245 K附近观测到相变引起的CsFAMA混合阳离子钙钛矿发光光谱红移现象。根据Saha-Langmuir方程计算结果,确认温度高于65 K时电子空穴复合主导CsFAMA混合阳离子钙钛矿发光过程。利用带间发光与带尾态发光组合模型拟合CsFAMA混合阳离子钙钛矿的发光光谱,得到65~295 K温度范围内的带尾态扩展程度E_(0)(0.023~0.045 eV)与载流子等效温度。根据CsFAMA混合阳离子钙钛矿的发光动力学曲线分析,确定电子空穴复合速率常数R_(eh)随热力学温度升高(65~295 K)而不断降低。本文实验结果表明,热力学温度升高引起的晶格振动加剧,有利于实现自由载流子与晶格间的热交换,但增加了体系的热无序度,抑制了电子空穴的辐射复合,加快了载流子的非辐射复合速率。In this paper,the luminescence process of Cs_(0.05)FA_(0.81)MA_(0.14)PbI_(2.55)Br_(0.45)(hereinafter referred to as CsFAMA mixed cationic perovskite)thin film was studied by steady-state and transient photoluminescence(PL)spectroscopy.The phase transition induced PL spectra red shift was observed at about 245 K.According to the results of Saha-Langmuir equation,it is confirmed that electron hole recombination dominates the luminescence process of CsFAMA mixed cation perovskite when the temperature is higher than 65 K.The PL spectra of CsFAMA mixed cation perovskite were fitted by the combined model of interband luminescence and band tail luminescence.The band tail extendsion E_(0)(0.023-0.045 eV)and the carrier equivalent temperature were obtained in the temperature range of 65-295 K.The experimental results show that the electron hole recombination rate constant R_(eh) decreases with the increase of thermodynamic temperature(65-295 K)on the basis of analysis of the luminescence kinetics curve of CsFAMA mixed cationic perovskite.The increase of thermodynamic temperature causes the enhancement of lattice vibration,which is conducive to the heat exchange between free carriers and lattice.Meanwhile it increases the thermal disorder,leading to suppress of electron and hole radiative recombination and accelerate of carrier nonradiative recombination.

关 键 词：发光 带尾态 热无序 相变 

分 类 号：O482.31[理学—固体物理]