High-performance Sb-doped p-ZnO NW films for self-powered piezoelectric strain sensors

Novel wide-bandgap piezoelectric semiconductor materials, with wurtzite structure, set a great impetus to research, which outreach the promising applications in optoelectronic devices, wearable electronic devices and medical monitoring systems. Here, we studied the piezotronic effect of p-ZnO NW films under strain which were suitable for self-powered tactile sensors. Typically, the doping level was 2 × 1017 cm−3 at the 2% Sb doping in solution. Based on different devices design, it was verified that the piezoelectric charges induced by applied strain could significantly affect the charge carrier separation and transport at the interface/junction. For p-ZnO NW thin film devices, the negative piezoelectric charge reduces Schottky barrier height, while the positive piezoelectric charge increases it. Self-powered strain sensors were then developed based on the changes of piezoelectric potential under different strain, which have a potential candidate for applications in man-machine interaction interface and biomedical sciences. The p-type semiconducting properties of the Sb-doped ZnO NW films prepared via the low-temperature solution method were verified by the p-n junction and the MIS junction. Piezoelectric effect in p-ZnO NW films was then theoretically analyzed and summarized through different device structures and metal electrodes. Self-powered strain sensors were finally constructed to meet the requirements of novel piezoelectric electronic devices. [Display omitted] •Synthesized ZnO NW films were qualitatively analyzed as p-type semiconductor by heterojunction structure.•The p-type semiconductor properties of ZnO was confirmed by MIS structure.•The piezoelectric effect of p-type ZnO NW films with different device structure was studied.•Self-powered strain sensors based on the piezoelectric potential were developed.