High detectivity and fast response avalanche photodetector based on GaSe/PtSe2 p–n junction

• Published in: Materials & design 2023-04, Vol.228, p.111848, Article 111848
• Main Authors: Gong, Kaiwen, Li, Lianbi, Yu, Wenzhi, Mu, Haoran, Yuan, Jian, Hao, Ran, Liu, Baiquan, Mei, Zengxia, Mei, Luyao, Li, Haozhe, Lin, Shenghuang
• Format: Article
• Language: English
• Subjects: 2D heterojunction; Avalanche photodetector; CVD; Mechanical exfoliation
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2023.111848

[Display omitted] •We investigated a synthesis method merging exfoliation and CVD to fabricate photodetectors of the GaSe/PtSe2 heterojunction.•The detectivity under avalanche mode is ∼ 3.51 × 1012 Jones at the bias voltage of −10 V.•A fast response time could be obtained around 20 μs. Heterojunction photodetectors based on 2D materials are a promising geometry to acquire broadband photodetection with combination of wide-bandgap and narrow bandgap functional materials. But the interface condition of the heterojunction is difficult to control due to the inevitable introduction of air bubbles and wrinkles. In this paper, a synthesis method merging exfoliation and CVD is reported to fabricate photodetectors of the GaSe/PtSe2 heterojunction. The devices present the highest responsivity and detectivity of about 1.7 A/W and 3.51 × 1012 Jones at a −10 V bias under the avalanche mode, respectively. Also, a fast response time could be obtained around 20 μs. In addition, the photodetector exhibits a clear photovoltaic effect, which can work in a self-powered mode.