Interfacial photoconductivity effect of type-Ⅰ and type-Ⅱ Sb2Se3/Si heterojunctions for THz wave modulation  

作　　者：曹雪芹 黄媛媛 席亚妍 雷珍 王静 刘昊楠 史明坚 韩涛涛 张蒙恩 徐新龙 Xue-Qin Cao;Yuan-Yuan Huang;Ya-Yan Xi;Zhen Lei;Jing Wang;Hao-Nan Liu;Ming-Jian Shi;Tao-Tao Han;Meng-En Zhang;Xin-Long Xu(Shaanxi Joint Laboratory of Graphene,State Key Laboratory Incubation Base of Photoelectric Technology and Functional Materials,International Collaborative Center on Photoelectric Technology,and Nano Functional Materials,Institute of Photonics&Photon-Technology,Northwest University,Xi’an 710069,China)

机构地区：[1]Shaanxi Joint Laboratory of Graphene,State Key Laboratory Incubation Base of Photoelectric Technology and Functional Materials,International Collaborative Center on Photoelectric Technology,and Nano Functional Materials,Institute of Photonics&Photon-Technology,Northwest University,Xi’an 710069,China

出　　处：《Chinese Physics B》2023年第11期82-86,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 12261141662, 12074311, and 12004310)。

摘　　要：An in-depth understanding of the photoconductivity and photocarrier density at the interface is of great significance for improving the performance of optoelectronic devices. However, extraction of the photoconductivity and photocarrier density at the heterojunction interface remains elusive. Herein, we have obtained the photoconductivity and photocarrier density of 173 nm Sb2Se3/Si(type-Ⅰ heterojunction) and 90 nm Sb2Se3/Si(type-Ⅱ heterojunction) utilizing terahertz(THz) time-domain spectroscopy(THz-TDS) and a theoretical Drude model. Since type-Ⅰ heterojunctions accelerate carrier recombination and type-Ⅱ heterojunctions accelerate carrier separation, the photoconductivity and photocarrier density of the type-Ⅱ heterojunction(21.8×10^(4)S·m^(-1),1.5 × 10^(15)cm^(-3)) are higher than those of the type-Ⅰ heterojunction(11.8×10^(4)S·m^(-1),0.8×10^(15)cm^(-3)). These results demonstrate that a type-Ⅱ heterojunction is superior to a type-Ⅰ heterojunction for THz wave modulation. This work highlights THz-TDS as an effective tool for studying photoconductivity and photocarrier density at the heterojunction interface. In turn, the intriguing interfacial photoconductivity effect provides a way to improve the THz wave modulation performance.

关 键 词：PHOTOCONDUCTIVITY Sb2 Se3/Si heterojunctions THZ-TDS Drude model 

分 类 号：O48[理学—固体物理] O441.4[理学—物理]