中国物理B ›› 2023, Vol. 32 ›› Issue (11): 116701-116701.doi: 10.1088/1674-1056/acf301

所属专题: SPECIAL TOPIC — Celebrating the 100th Anniversary of Physics Discipline of Northwest University

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

Xue-Qin Cao(曹雪芹), Yuan-Yuan Huang(黄媛媛), Ya-Yan Xi(席亚妍), Zhen Lei(雷珍), Jing Wang(王静), Hao-Nan Liu(刘昊楠), Ming-Jian Shi(史明坚), Tao-Tao Han(韩涛涛), Meng-En Zhang(张蒙恩), and Xin-Long Xu(徐新龙)   

  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
  • 收稿日期:2023-06-26 修回日期:2023-08-12 接受日期:2023-08-23 出版日期:2023-10-16 发布日期:2023-10-31
  • 通讯作者: Yuan-Yuan Huang, Xin-Long Xu E-mail:yyhuang@nwu.edu.cn;xlxuphy@nwu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12261141662, 12074311, and 12004310).

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

Xue-Qin Cao(曹雪芹), Yuan-Yuan Huang(黄媛媛), Ya-Yan Xi(席亚妍), Zhen Lei(雷珍), Jing Wang(王静), Hao-Nan Liu(刘昊楠), Ming-Jian Shi(史明坚), Tao-Tao Han(韩涛涛), Meng-En Zhang(张蒙恩), and Xin-Long Xu(徐新龙)   

  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
  • Received:2023-06-26 Revised:2023-08-12 Accepted:2023-08-23 Online:2023-10-16 Published:2023-10-31
  • Contact: Yuan-Yuan Huang, Xin-Long Xu E-mail:yyhuang@nwu.edu.cn;xlxuphy@nwu.edu.cn
  • Supported by:
    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× 104 S·m-1, 1.5× 1015 cm-3) are higher than those of the type-I heterojunction (11.8× 104 S·m-1, 0.8× 1015 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, Sb2Se3/Si heterojunctions, THz-TDS, Drude model

Abstract: 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× 104 S·m-1, 1.5× 1015 cm-3) are higher than those of the type-I heterojunction (11.8× 104 S·m-1, 0.8× 1015 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.

Key words: photoconductivity, Sb2Se3/Si heterojunctions, THz-TDS, Drude model

中图分类号:  (Interfaces)

  • 67.30.hp
68.35.Fx (Diffusion; interface formation) 79.60.Jv (Interfaces; heterostructures; nanostructures)