Al-Doped ZnO Nanowires by Electrochemical Deposition for Selective VOC Nanosensor and Nanophotodetector

Abstract

Nanomaterials for new nanosensor systems with selective detection of hazardous volatile organic compounds (VOCs) vapors are of great demand nowadays. In this paper, the use in nanosensors of electrochemically deposited (ECD) Al-doped ZnO (ZnO:Al) nanowires (NWs) is reported. The NWs are characterized by micro-Raman and optical measurements. Individual ZnO and ZnO:Al NWs are integrated into nanosensor devices for room temperature UV and gas sensing. It is shown that, compared to undoped ZnO NW with irreversible response, the doped ZnO:Al NWs have faster response (≈5 s) and recovery (≈55 s), as well as enhanced UV response (≈4.8, about 2 times higher). The room temperature gas sensing investigations demonstrate that an individual ZnO:Al NW can detect volatile organic compounds (VOCs) vapors such as 2-propanol, n-butanol and ethanol at room temperature with a relatively fast response time of ≈10 s and a reversible signal (the recovery time being 30–40 s). This shows the possibility to use it with further development as indoor air quality monitor.