基于瞬态吸收光谱的Sb_(2)Se_(3)载流子复合过程  

Carrier recombination processes in Sb_(2)Se_(3)based on transient absorption spectroscopy

作　　者：冯博浩 党伟[1] 莫安明 董汶鑫 李志强[1] 赵晓辉[1] FENG Bohao;DANG Wei;MO Anming;DONG Wenxin;LI Zhiqiang;ZHAO Xiaohui(Hebei Provincial Key Laboratory of Optoelectronic Information Materials,College of Physics Science and Technology,Hebei University,Baoding 071002,China)

机构地区：[1]河北大学物理科学与技术学院,河北省光电信息材料重点实验室,河北保定071002

出　　处：《河北大学学报(自然科学版)》2025年第1期34-42,共9页Journal of Hebei University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(12275065);中央引导地方科技发展资金资助项目(236Z4305G);河北省光电信息材料重点实验室项目(22567634H)。

摘　　要：了解Sb_(2)Se_(3)中的载流子复合过程对提高其光电性能至关重要.飞秒瞬态吸收光谱(fs-TAS)凭借高分辨率的优点能够获得丰富的光学信息,是研究Sb_(2)Se_(3)载流子复合过程的有力工具.本文测得不同激发波长和激发密度下的多晶Sb_(2)Se_(3)薄膜的宽带瞬态吸收光谱.首先证实在长时间尺度下(时间延迟大于10 ps)探测光为650~1100 nm激发态吸收信号源于深束缚载流子吸收作用,并将短时间尺度下(时间延迟小于10 ps)探测光为900~1050 nm激发态信号归因于浅束缚载流子吸收.通过Sb_(2)Se_(3)的瞬态吸收动力学曲线,提取出其自由载流子寿命和热载流子冷却时间:在激发波长为950 nm条件下,自由载流子平均寿命为35.28~54.23 ps,随着激发密度增加而减小;在激发波长为550 nm和750 nm条件下,热载流子冷却时间为0.17~0.48 ps,与激发密度成正比.Understanding the carrier recombination processes in Sb_(2)Se_(3)is crucial for enhancing its optoelectronic performance.Femtosecond transient absorption spectroscopy(fs-TAS),with its high-resolution advantages,provides rich optical information and serves as a powerful tool for investigating carrier recombination processes in Sb_(2)Se_(3).This study obtained broadband transient absorption spectra of polycrystalline Sb_(2)Se_(3)thin films under different excitation wavelengths and excitation densities.It was first confirmed that the excited-state absorption signals in the 650—1100 nm range on longer time scales(time delay greater than 10 ps)originated from deep-bound carrier absorption,while the excited-state signals in the 900—1050 nm range on shorter time scales(time delay less than 10 ps)were attributed to shallow-bound carrier absorption.Through the transient absorption dynamics of Sb_(2)Se_(3),this study extracted the lifetimes of the free carriers and the cooling time of the hot carriers.Under 950 nm excitation,the average lifetime of free carriers ranged from 35.28 to 54.23 ps and decreased with increasing excitation density.Under 550 nm and 750 nm excitation,the time constant of hot carrier cooling times was in range of 0.17—0.48 ps and was proportional to the excitation density.

关 键 词：Sb_(2)Se_(3) 载流子复合 瞬态吸收光谱 自由载流子寿命 热载流子冷却 

分 类 号：O472[理学—半导体物理]