Piezotronic effect enhanced performance of Schottky-contacted optical, gas, chemical and biological nanosensors

In this review, we systematically analyze the enhanced performances of Schottky-structured nanowire sensors by the piezotronic effect. Compared with traditional Ohmic-contact nanowire sensing systems, Schottky-contact provides ultra-high sensitivity and superfast response depending on the barrier height at local metal-semiconductor (M-S) interface. Utilizing the strain-induced piezoelectric polarization charges presented at the vicinity of M-S contact, piezotronic effect is applied to tune/control the charge carriers transport process through the interface by modulating the Schottky barrier height (SBH) at local contact, and thus hugely enhances the performances of Schottky-structured sensors. Our results indicate that piezotronic effect is a universal effect that provides an effective approach to improve the sensitivity, resolution, response time and other general properties of Schottky-contact nanowire sensors in different categories, including bio/chemical sensing, gas sensing, humidity sensing, temperature sensing and others.