Sb_(2)Se_(3)薄膜表面和界面超快载流子动力学的瞬态反射光谱分析  

Ultrafast carrier kinetics at surface and interface of Sb_(2)Se_(3) film by transient reflectance

作　　者：黄昊 牛奔 陶婷婷 罗世平 王颖[1] 赵晓辉[1] 王凯 李志强[1] 党伟[1] Huang Hao;Niu Ben;Tao Ting-Ting;Luo Shi-Ping;Wang Ying;Zhao Xiao-Hui;Wang Kai;Li Zhi-Qiang;Dang Wei(Hebei Key Laboratory of Optic-Electronic Information and 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,保定071002

出　　处：《物理学报》2022年第6期200-211,共12页Acta Physica Sinica

基　　金：国家科技支撑计划(批准号:2019YFB503404);国家自然科学基金青年科学基金(批准号:21503066);河北省教育厅重点项目(批准号:ZD2019037);河北省自然科学基金杰出青年基金(批准号:F2019201289);河北省自然科学基金青年项目(批准号:F2017201136)资助的课题.

摘　　要：Sb_(2)Se_(3)是一种低成本、环境友好、具有良好应用前景的光伏材料.目前Sb_(2)Se_(3)太阳能电池的光电转换效率已经提高到了10%.载流子复合动力学是决定Sb_(2)Se_(3)太阳能电池光电转换效率的关键因素.本文利用飞秒时间分辨表面瞬态反射谱详细分析了Sb_(2)Se_(3)表面、Sb_(2)Se_(3)/CdS界面载流子复合动力学过程.根据相对反射率变化△R/R的演化,得到Sb_(2)Se_(3)载流子热化、带隙收缩时间约为0.2-0.5 ps,估计热载流子冷却时间为3-4 ps.还实验证实在Sb_(2)Se_(3)/CdS界面处存在自由电子转移和浅束缚电子转移两种电子转移过程.本文提供了Sb_(2)Se_(3)表面瞬态反射谱分析方法,所得实验结果拓展了对Sb_(2)Se_(3)表面及Sb_(2)Se_(3)/CdS界面载流子过程的理解.Antimony selenide(Sb_(2)Se_(3))is a promising low-cost and environmentally-friendly semiconductor photovoltaic material.The power conversion efficiency of Sb_(2)Se_(3) solar cells has been improved to 10%in the past few years.The carrier recombination transfer dynamics is significant factor that affects the efficiency of Sb_(2)Se_(3) solar cells.In this work,carrier recombination on the Sb_(2)Se_(3) surface and carrier transfer dynamics at the CdS/Sb_(2)Se_(3) heterojunction interface are systematically investigated by surface transient reflectance.According to the evolution of relative reflectance change ΔR/R ,the carrier thermalization and band gap renormalization time of Sb_(2)Se_(3) are determined to be in a range from 0.2 to 0.5 ps,and carrier cooling time is estimated to be about 3-4 ps.Our results also demonstrate that both free electron and shallow-trapped electron transfer occur at the Sb_(2)Se_(3)/CdS interface after photo excitation.Our results present a method of explaining the transient reflectance of Sb_(2)Se_(3) and enhancing the understanding of carrier kinetics at Sb_(2)Se_(3) surface and Sb_(2)Se_(3)/CdS interface.

关 键 词：Sb_(2)Se_(3) 表面瞬态反射 载流子复合 电子转移 

分 类 号：TM914.4[电气工程—电力电子与电力传动]