Performance enhancement of a hydrothermally grown ZnO-based ultraviolet photodetector using substrate transfer and pyramid-like surface texture. (26th March 2019)

• Record Type: Journal Article
• Authors: Hung, Ying-Chi; Wang, Shui-Jinn; Ko, Rong-Ming; Wang, Sheng-Yi; You, Bing-Cheng; Chen, Hsiang-Yi; Liao, Chun-Kai; Hsiao, Sheng-Tsang
• Is Part Of: Japanese journal of applied physics. Volume 58:Number SB(2019)
• Publication Date: 2019-03-26
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/1347-4065/aaffbc
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: A comparative study of the performance of lateral- and vertical-structured UV photodetectors (PDs) based on a hydrothermally grown (HTG) n-ZnO/sputtered p-CuO heterojunction (HJ) is presented. After substrate transfer (ST) conducted using a sonicating bath process, the vertical-structured UV PD showed a fast response and a 310-fold improvement in light responsivity compared with that of the lateral-structured UV PD under UV illumination (365 nm at 3 mW cm −2 ) at a reverse bias of −1 V. This improvement is attributed to the much shorter conduction path and lake of a seed layer for the vertical structure. With further surface chemical etching of the HTG n-ZnO layer after ST, a pyramid-like surface texture formed and a significantly enhanced UV light response (as high as 943-fold higher) was obtained. The increase in photo-responsivity is due to the removal of the high defect density initial ZnO growth layer and reduced light reflection.