甲脒铅溴钙钛矿纳米晶的瞬态吸收与温度依赖光致发光  

Transient Absorption and Temperature Dependent Photoluminescence of Formamidinium Lead Bromide Perovskite Nanocrystals

作　　者：王亚娟[1] 赵军伟[1] 季丰民[1] 王芳[1] 刘威 WANG Yajuan;ZHAO Junwei;JI Fengmin;WANG Fang;LIU Wei(School of Materials and Chemical Engineering,Ningbo University of Technology,Ningbo 315211,China;College of Optical,Mechanical and Electrical Engineering,Zhejiang A&F University,Hangzhou 311300,China)

机构地区：[1]宁波工程学院材料与化学工程学院,浙江宁波315211 [2]浙江农林大学光机电工程学院,浙江杭州311300

出　　处：《发光学报》2024年第10期1587-1597,共11页Chinese Journal of Luminescence

基　　金：中国林科院-浙江省省院合作青年人才项目(2023SY14)。

摘　　要：甲脒铅溴钙钛矿纳米晶(FAPbBr_(3) NCs)因其在光电应用中的卓越性能而受到广泛关注。使用铵作为配体对钙钛矿纳米晶进行有效表面钝化被证明是提高器件性能的有效方法。本文使用配体辅助再沉淀技术制备了两种不同胺配体(长链油胺和短链己胺)的FAPbBr_(3) NCs,通过瞬态吸收光谱和时间分辨光致发光研究它们的激发态载流子动力学。结果显示,油胺配体的NCs具有更长的载流子寿命与较慢的载流子弛豫动力学,表明长链油胺能有效钝化表面缺陷,促进辐射复合。通过稳态光致发光光谱实验研究了FAPbBr_(3) NCs的温度依赖性,结果表明随着温度升高,激子-声子耦合增强,线宽和发射峰的光子能量增加,确定了长链油胺配体FAPbBr_(3) NCs中的激子结合能约为62.9 meV及纵向光学声子能量约为30.5 meV。研究结果证实了胺配体在调控FAPbBr_(3) NCs光学性能方面的作用,为高性能光电器件的设计提供了重要的指导意义。Formamidinium lead bromide perovskite nanocrystals(FAPbBr_(3) NCs)have attracted widespread attention due to their excellent performance in optoelectronic applications.Notably,the utilization of amines as ligands for effective surface passivation of perovskite nanocrystals has been proven to be an effective method for enhancing device performance.In this work,FAPbBr_(3) NCs with two different amine ligands(long-chain oleylamine and short-chain hexylamine)were prepared using ligand-assisted reprecipitation technology.Their excited-state carrier dynamics were studied by transient absorption(TA)spectroscopy and time-resolved photoluminescence(TRPL),revealing that NCs with oleylamine ligands exhibit longer carrier lifetime and slower carrier relaxation dynamics,indicating that long-chain oleylamine can effectively passivate surface defects and promote radiative recombination.The temperature dependence of FAPbBr_(3) NCs was investigated using steady-state photoluminescence spectroscopy.The results showed that as the temperature increases,exciton-phonon coupling is enhanced,leading to an increase in linewidth and photon energy of the emission peak.The exciton binding energy in long-chain oleylamine-ligated FAPbBr_(3) NCs was determined to be approximately 62.9 meV,and the longitudinal optical phonon energy was approximately 30.5 meV.The research results confirm the role of amine ligands in regulating the optical properties of FAPbBr_(3) NCs,providing important guidance for the design of high-performance optoelectronic devices.

关 键 词：钙钛矿纳米晶 瞬态吸收 飞秒激光激发 载流子动力学 

分 类 号：O482.31[理学—固体物理]