Controlled Synthesis of Bi<sub>2</sub>O<sub>2</sub>Te Nanosheets for High-Performance Broadband Photodetectors
Shijie Duan, Tiange Zhao, Xun Ge, Maohua Chen, Yuzhuo Bai, Yiye Yu, Shikun Duan, Yue Chen, Xingbo Shang, Longhai Zhu, Meng Yuan, Ziyi Fu, Zhen Wang, Jun Wang
Abstract
Broadband photodetectors, covering visible to infrared spectra, are widely used in communications, imaging, military, and the medical fields. Recently, low-dimensional material-based photodetectors have gained significant attention. Low-dimensional Bi 2 O 2 Se has been extensively studied for its excellent air stability and optical properties. Similarly, Bi 2 O 2 Te shares these advantages and has a narrower band gap of 0.13 eV. However, research on Bi 2 O 2 Te remains limited, likely due to its challenging synthesis conditions, which have impeded the study of its optoelectronic properties. In this study, we successfully synthesized large-scale (235 μm, the largest reported to date) Bi 2 O 2 Te nanosheets using an upside-down growth chemical vapor deposition method. Furthermore, the fabricated Bi 2 O 2 Te photodetector exhibits broadband photoresponse (520 nm-2 μm), an ultrahigh responsivity of 3679 A W –1, an impressive detectivity of 8.91 × 10 11 cm Hz 1/2 W –1, and a fast response time (τ rise /τ decay ≈ 32/92 μs), demonstrating its potential for applications in high-performance photodetectors. More importantly, this work provides a significant contribution to the further investigation of Bi 2 O 2 Te.