ZnO nanowire array ultraviolet photodetectors with self-powered properties

A ZnO nanowire (NW) array ultraviolet photodetector (PD) with Pt Schottky contacts has been fabricated on a glass substrate. Under UV light illumination, this PD showed a high photo-to-dark current ratio of 892 at 30 V bias. Interestingly, it was also found that this PD had a high sensitivity of 475 without external bias. This phenomenon could be explained by the asymmetric Schottky barrier height (SBH) at the two ends causing different separation efficiency of photogenerated electron–hole pairs, which resulted in the formation of photocurrent. It is anticipated to have potential applications in self-powered UV detection field.

► High quality ZnO nanowire arrays are fabricated by hydrothermal synthesis.
► The photodetector shows a high photo-to-dark current ratio of 892 under UV illumination.
► The photodetector is self-powered under UV illumination.
► The photoconduction mechanism is used to explain the self-powered phenomenon.