School of Advanced Materials Science and Engineering, Sungkyunkwan University, Jangan-gu, Suwon, Gyeonggi-do, Republic of Korea.
Nanotechnology. 2011 Jul 1;22(26):265506. doi: 10.1088/0957-4484/22/26/265506. Epub 2011 May 18.
This study reports that the visible-blind ultraviolet (UV) photodetecting properties of ZnO nanowire based photodetectors were remarkably improved by introducing ultrathin insulating MgO layers between the ZnO nanowires and Si substrates. All layers were grown without pause by metal organic chemical vapor deposition and the density and vertical arrangement of the ZnO nanowires were strongly dependent on the thickness of the MgO layers. The sample in which an MgO layer with a thickness of 8 nm was inserted had high density nanowires with a vertical alignment and showed dramatically improved UV photosensing performance (photo-to-dark current ratio = 1344.5 and recovery time = 350 ms). The photoresponse spectrum revealed good visible-blind UV detectivity with a sharp cut off at 378 nm and a high UV/visible rejection ratio. A detailed discussion regarding the developed UV photosensing mechanism from the introduction of the i-MgO layers and highly dense nanowires in the n-ZnO nanowires/i-MgO/n-Si substrates structure is presented in this work.
本研究报告指出，通过在 ZnO 纳米线和 Si 衬底之间引入超薄绝缘 MgO 层，基于 ZnO 纳米线的光电探测器的可见盲紫外（UV）光电探测性能得到显著提高。所有层均通过金属有机化学气相沉积不间断生长，并且 ZnO 纳米线的密度和垂直排列强烈依赖于 MgO 层的厚度。在插入厚度为 8nm 的 MgO 层的样品中，具有高垂直排列的高密度纳米线，并表现出显著改善的 UV 光感测性能（光电流与暗电流比=1344.5，恢复时间=350ms）。光响应光谱显示出良好的可见盲紫外探测性能，在 378nm 处具有陡峭的截止，以及高的 UV/可见光抑制比。在本工作中，从 i-MgO 层的引入和 n-ZnO 纳米线/i-MgO/n-Si 衬底结构中高密度纳米线的角度，详细讨论了所开发的 UV 光感测机制。
