Rationally designed state-of-the-art approach for enhancing the ultraviolet photon detection performance of ZnO thin film

Abstract

Here, we demonstrate a simple and effective state-of-the-art (surface passivation) approach for enhancing the UV photo detection performance of ZnO thin films synthesized via spray pyrolysis. The surface passivated Ag/ZnO/Ag device (using polyvinyl alcohol layer) has low dark current of 1.1 nA as compared with the device without surface passivation (0.04 μA). The significant decay in the dark current after surface passivation is due the reduction in the density of surface oxygen vacancies confirmed by PL measurements. The UV photon detection capability of the surface passivated ZnO thin film exhibits a significantly high photo response (3675), high photosensitivity (3.6 × 105), photo-responsivity (0.6 A/W) and fast response time (0.6 ms) under UV light (340 nm, 140 μW/cm2). This straightforward approach superimposes surface defects, making the ZnO thin film more suitable for a wide range of electronic device applications while preserving the material's intrinsic properties.