Carrier-recirculating broadband photodetector with high gain based on van der Waals In2Se3/MoS2 heterostructure

• Published in: Applied surface science 2024-03, Vol.649, p.159135, Article 159135
• Main Authors: Li, Peipei, Wang, Tongling, Wang, Ancheng, Zhao, Le, Zhu, Yanqin, Wang, Zhaowei, Gao, Honglei, Wang, Wenjia, Li, Kuilong, Du, Changhui
• Format: Article
• Language: English
• Subjects: 2D materials; Broadband photodetection; Optical gain; Photogating effect; β-In2Se3/MoS2 heterostructure
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2023.159135

[Display omitted] •In the prepared β-In2Se3/MoS2 photodetector, the photogenerated electrons can be cycled multiple times in the channel to achieving high gain of 2.95 × 103.•From the visible to the near-infrared region, the dominated mechanism of photocurrent generation shifts from photogating effect to photoconductive effect.•The photoresponse spectrum of In2Se3/MoS2 heterojunction is further extended to 1310 nm. Two-dimensional (2D) materials present enormous potential in photoelectric detection, medical imaging, and neuromorphic vision applications due to their superior electronic and optoelectronic properties. Nevertheless, the photoelectric performance is restricted by the short lifetime of photogenerated carriers and weak optical absorption attributed to the atomic-scale thickness. This work demonstrates a novel high-gain photodetector based on van der Waals β-In2Se3/MoS2 heterostructure induced by carrier recirculation. In this structure, the photoexcited holes are trapped in the charge traps of MoS2 driven by the built-in electric field, which suppresses the recombination of photogenerated carriers, thus the electrons are repeatedly recycled across the In2Se3 channel after the generation of electron-hole pairs, achieving the high optical gain of 2.95 × 103. The responsivity, external quantum efficiency and specific detectivity of In2Se3/MoS2 photodetector can reach 616.77 A/W, 125900 %, and 1.03 × 1012 Jones at 638 nm, respectively, which are significantly higher than those of individual In2Se3 and MoS2 photodetector. More significantly, due to the enhanced optical absorption and interlayer transition, the photoresponse spectrum of In2Se3/MoS2 heterojunction is further extended to 1310 nm, which can be applied to broadband photodetection. Therefore, the In2Se3/MoS2 vdWs heterojunction photodetector provides a feasible approach to fabricate high-performance broadband photodetectors.