ZnO branched p-CuxO @n-ZnO heterojunction nanowires for improving acetone gas sensing performance

A simple and effective preparation method was proposed to improve acetone gas sensing performance based on ZnO branched p-CuxO@n-ZnO nanowires (NWs) by hydrothermal processing and atomic layer deposition technique. The gas sensor was fabricated on micro-electromechanical systems with lower power consumption and better integrated circuit compatibility. Compared with bare CuxO NWs and p-CuxO@n-ZnO core-shell NWs, the designed ZnO branched p-CuxO@n-ZnO NWs have higher gas response and better selectivity to acetone. The response value of the branched p-CuxO@n-ZnO NWs based sensor to 50 ppm acetone at the optimal temperature of 250 degrees C is approximately 6.4, which is 5 and 3.5 times of the devices with pristine CuxO and p-CuxO@n-ZnO core-shell NWs, respectively. The sensitivity enhancement mechanism of branched NWs is explained based on the depletion principle and the increased specific surface area. It is expected that the proposed ZnO branched p-CuxO@n-ZnO NWs has a good reference for the development of high sensitivity and selectivity gas sensors.