CSIR-National Physical Laboratory, Dr K. S. Krishnan Marg, New Delhi 110012, India. Academy of Scientific and Innovative Research (AcSIR), CSIR-National Physical Laboratory, Dr K. S. Krishnan Marg, New Delhi 110012, India.
Nanotechnology. 2020 Jan 10;31(2):025705. doi: 10.1088/1361-6528/ab474e. Epub 2019 Oct 11.
Zinc oxide (ZnO) one-dimensional nanostructures are extensively used in ultra-violet (UV) detection. To improve the optical sensing capability of ZnO, various nickel oxide (NiO) based p-n junctions have been employed. ZnO/NiO heterojunction based sensing has been limited to UV detection and not been extended to the visible region. In the present work, p-NiO/n-ZnO composite nanowire (NW) heterojunction based UV-visible photodetector is fabricated. A porous anodic aluminum oxide template based electrochemical deposition method is adopted for well separated and vertically aligned growth of composite NWs. The photoresponse is studied in an out of plane contact configuration. The fabricated photodetector shows fast response under UV-visible light with a rise and decay time of tens of ms. The wide spectral photoresponse is analyzed in terms of conduction from defect states of ZnO and interfacial defects during p-n junction formation. Light interaction with heterojunction along the length of the composite NW results in enhanced visible photoresponse of the detector and is further supported by simulation.
氧化锌 (ZnO) 一维纳米结构被广泛应用于紫外 (UV) 检测。为了提高 ZnO 的光学传感性能，已经采用了各种氧化镍 (NiO) 基 p-n 结。基于 ZnO/NiO 异质结的传感仅限于 UV 检测，尚未扩展到可见光区域。在本工作中，制备了基于 p-NiO/n-ZnO 复合纳米线 (NW) 异质结的 UV-可见光电探测器。采用多孔阳极氧化铝模板的电化学沉积方法实现了复合 NW 的良好分离和垂直生长。在面外接触配置下研究了光响应。所制备的光电探测器在 UV-可见光下具有快速的响应，上升和下降时间为几十毫秒。根据 ZnO 的缺陷态和 p-n 结形成过程中界面缺陷的传导，分析了宽光谱光响应。光与复合 NW 长度方向上的异质结相互作用导致探测器的可见光响应增强，这一结果得到了模拟的支持。
