High-performance solution-processed ZnSnO metal–semiconductor–metal ultraviolet photodetectors via ultraviolet/ozone photo-annealing
Chun‐Ying Huang, Lian-Kai Xiao, Yun-Hsiang Chang, Liang-Yü Chen, Guan-Ting Chen, Ming-Hsien Li
Abstract
Abstract In-free amorphous oxide semiconductors (AOS), such as ZnSnO (ZTO) are solution-processed for use in transistors and photodetectors (PDs). However, the device performance is much lower than that for a device that uses an In-based AOS (e.g. a-InGaZnO). This study determines the effect of ultraviolet (UV)/ozone (O 3 ) optical-annealing treatment on In-free amorphous ZnSnO (ZTO) metal–semiconductor–metal PDs using a sol–gel method. UV/O 3 optical-annealing for ZTO gel films allows the condensation process to be completed because organic- and hydrogen-based elements are fully decomposed, so the PDs have a relatively high responsivity of 11.3 A W −1 , an ultra-high photo-to-dark current ratio of 2090 and an improved response speed, with a decay time of 3.02 s. This work uses the UV/O 3 technique for AOS-based UV PDs and shows the potential for developing In-free AOS for other electronic and optoelectronic devices.