Low-Temperature Solution-Processed ZnSnO Ozone Gas Sensors Using UV-Assisted Thermal Annealing

Ultraviolet-assisted thermal annealing (UVTA) has been widely used to fabricate solution-processed amorphous oxide semiconductor (AOS)-based transistors and photodetectors. However, this method has not been used for AOS-based gas sensors, even though AOS is a good gas sensing material. This study determines the effect of UVTA on the electrical properties of In-free amorphous ZnSnO (ZTO) thin films and their ozone (O-3) gas sensing characteristics. UV light from a Mercury lamp has sufficient energy to decompose the organic- and hydrogen-based impurities completely, which promotes the formation of metal oxide networks, so the quality of ZTO films is greatly increased by increasing treatment time. A relatively high gas response of 1.42 with a fast response/recovery time (124/78 s) is achieved. This strategy allows the fabrication of ZTO gas sensors at low temperature (150 degrees C) and is applicable to flexible electronics.

Automated summary

In this study, the effects of UVTA on the electrical properties of In-free amorphous ZnSnO thin films were investigated. It was found that UVTA greatly improved the quality of the films and enhanced their gas sensing characteristics. The strategy of UV-assisted thermal annealing allows for the fabrication of gas sensors at low temperature and is applicable to flexible electronics.