Yang Junda, Zhang Fen, Liu Shuo, Zhou Xinyun, Yang Jiacheng, Xia Qinglin, Zhong Mianzeng
Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha 410083, China.
Nanoscale. 2025 Apr 10;17(15):9346-9354. doi: 10.1039/d4nr05031b.
Bismuth selenide (BiSe) has emerged as a promising material for high-performance photodetectors due to its wideband spectral response, strong in-plane anisotropy, narrow bandgap, high absorption coefficient, and carrier mobility. However, inherent defects and states in BiSe-based devices reduce optical conversion efficiency and stability. To address these challenges, we report the design and preparation of BiSeS nanowires by a facile chemical vapor transport method. The individual BiSeS nanowire photodetectors exhibit remarkable photoresponse over a broadband wavelength region ranging from ultraviolet C (254 nm) to near-infrared (1064 nm) with a low dark current of 0.015 nA and the measured maximum photoresponsivity of 2.52 A W at 532 nm, together with a detectivity of around 5.2 × 10 Jones. Furthermore, the photoresponse of photodetectors exhibits polarization angle sensitivity within a broadband range of 355 to 808 nm. The structural anisotropy of the BiSeS crystal leads to a maximum dichroic ratio of about 1.8 at 355 nm. Additionally, cat images produced by this device further demonstrate the potential of the high-performance devices, and the effectiveness of photodetectors in deep learning image recognition validates their wide-spectrum, high-responsivity, and superior polarization-sensitive detection capabilities.
硒化铋（BiSe）因其宽带光谱响应、强面内各向异性、窄带隙、高吸收系数和载流子迁移率，已成为一种用于高性能光电探测器的有前景的材料。然而，基于BiSe的器件中的固有缺陷和态会降低光转换效率和稳定性。为应对这些挑战，我们报道了通过一种简便的化学气相传输方法设计和制备BiSeS纳米线。单个BiSeS纳米线光电探测器在从紫外C（254 nm）到近红外（1064 nm）的宽带波长区域表现出显著的光响应，暗电流低至0.015 nA，在532 nm处测得的最大光响应度为2.52 A/W，探测率约为5.2×10琼斯。此外，光电探测器的光响应在355至808 nm的宽带范围内表现出偏振角敏感性。BiSeS晶体的结构各向异性导致在355 nm处的最大二向色比约为1.8。此外，该器件产生的猫图像进一步证明了高性能器件的潜力，并且光电探测器在深度学习图像识别中的有效性验证了它们的广谱、高响应度和卓越的偏振敏感检测能力。
