LAUSR

Abstract Herein, a comparative study focusing on the effects of measuring atmosphere on ultraviolet (UV) photodetection performance of ZnO nanostructures is presented. Various morphologies of ZnO nanostructures were synthesized by changing the hydrothermal temperature within 343–423 K. The ultraviolet photodetection performance of the samples was studied against dark ultraviolet light (360 nm, 800 μW/cm2) under 200 sccm gas flows of argon and oxygen. The nanoflowers grown at 373 and 393 K showed the best photosensitivity and photoresponsivity under both argon and oxygen flows. Concerning the importance of active surface area, it was shown that the sample grown at 393 K serves higher accessible surface-to-volume ratio (qualitatively observable by SEM and confirmed by BET), higher concentration of freed electron due to oxygen vacancies (confirmed by PL) and consequently, the best UV photosensitivity. The comparative study between photodetection parameters in argon and oxygen atmospheres showed that although higher partial pressure of oxygen is favorable for all photodetection parameters like photosensitivity, photoresponsivity and decay time, it has adverse effects on rising time because rising time is directly coupled with the density of desorbed oxygen atoms.