UV‐activated room temperature single‐sheet ZnO gas sensor

Abstract

Room temperature sensor is a research hot for metal–oxide gas sensors. However, electron activation is a bottleneck to improve sensitivity for room temperature sensors. Here, an ultraviolet (UV)‐activated gas sensor based on a single‐sheet porous single‐crystalline (PSC) zinc oxide (ZnO) sheet has been fabricated instead of heating activation, which works at room temperature. The PSC ZnO nanosheets were first prepared by a one‐pot wet‐chemical method. Then, the precursors were annealed for 2 h in air to obtain the PSC ZnO nanosheets. They were characterised by scanning electron microscopy, high‐resolution transmission electron microscopy and UV–visible spectrum. Finally, the single‐sheet ZnO gas sensors were fabricated by focused ion beam technology, which exhibited good responses to 1–300 ppm of ethanol. The single‐sheet ZnO UV‐activated sensing mechanism was also put forward to explain the excellent sensing property.