Effect of surface oxygen vacancy defects on the performance of ZnO quantum dots ultraviolet photodetector

• 作者: Hongyu Ma Kewei Liu Zhen Cheng Zhiyao Zheng Yinzhe Liu Peixuan Zhang Xing Chen Deming Liu Lei Liu Dezhen Shen
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（8）
• 所属期刊栏目: CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
• 页码范围: 541-546
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/ac0131

摘要

The slower response speed is the main problem in the application of ZnO quantum dots (QDs) photodetector,which has been commonly attributed to the presence of excess oxygen vacancy defects and oxygen adsorption/desorption pro-cesses.However,the detailed mechanism is still not very clear.Herein,the properties ofZnO QDs and their photodetectors with different amounts of oxygen vacancy (Vo) defects controlled by hydrogen peroxide (H2O2) solution treatment have been investigated.After H2O2 solution treatment,Vo concentration of ZnO QDs decreased.The H2O2 solution-treated device has a higher photocurrent and a lower dark current.Meanwhile,with the increase in Vo concentration of ZnO QDs,the response speed of the device has been improved due to the increase of oxygen adsorption/desorption rate.More inter-estingly,the response speed of the device became less sensitive to temperature and oxygen concentration with the increase of VO defects.The findings in this work clarify that the surface Vo defects of ZnO QDs could enhance the photoresponse speed,which is helpful for sensor designing.