Broadband Bi2O2Se Photodetectors from Infrared to Terahertz. (29th January 2021)

• Record Type: Journal Article
• Authors: Chen, Yunfeng; Ma, Wanli; Tan, Congwei; Luo, Man; Zhou, Wei; Yao, Niangjuan; Wang, Hao; Zhang, Lili; Xu, Tengfei; Tong, Tong; Zhou, Yong; Xu, Yongbing; Yu, Chenhui; Shan, Chongxin; Peng, Hailin; Yue, Fangyu; Wang, Peng; Huang, Zhiming; Hu, Weida
• Is Part Of: Advanced functional materials. Volume 31:Number 14(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-01-29
• Subjects: Bi 2O 2Se -- broadband photodetector -- infrared/terahertz detection -- THz imaging; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202009554
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: 2D Bi2 O2 Se has shown great potential in photodetector from visible to infrared (IR) owing to its high mobility, ambient stability, and layer‐tunable bandgaps. However, for the terahertz (THz) band with longer wavelength and richer spectral information, there are few reports on the research of THz detection based on 2D materials. Herein, an antenna‐assisted Bi2 O2 Se photodetector is constructed to achieve broadband photodetection from IR to THz ranges driven by multi‐mechanism of electromagnetic waves to electrical conversion. The good tradeoff between the bandgap and high mobility results in a broad spectral detection. In the IR region, the nonequilibrium carriers result from photo‐induced electron‐hole pairs in the Bi2 O2 Se body. While in the THz region, the carriers are caused by the injected electrons from the metal electrodes by the electromagnetic‐induced well. The Bi2 O2 Se photodetector achieves a broadband responsivity of 58 A W ‐1 at 1550 nm, 2.7 × 10 4 V W ‐1 at 0.17 THz, and 1.9 × 10 8 V W ‐1 at 0.029 THz, respectively. Surprisingly, an ultrafast response time of 476 ns and a quite low noise equivalent power of 0.2 pW Hz −1/2 are acquired at room temperature. Our researches exhibit promising prospects of Bi2 O2 Se in broadband detection, THz imaging, and ultrafast sensing. Abstract : A room‐temperature 2D Bi2 O2 Se photodetector with ultrafast (476 ns) and ultralow noise (0.2 pW Hz –1/2 ) is demonstrated for broadband detection. The photoresponse of the devices in the IR (940–1550 nm) and THz (0.168–0.17 and 0.02–0.04 THz) regions are driven by multi‐mechanisms. Meanwhile, the Bi2 O2 Se THz photodetector exhibits excellent optoelectronic properties, polarized sensitivity, and high‐resolution imaging.