Ultrahigh Sensitive Piezotronic Strain Sensors Based on a ZnSnO3 Nanowire/Microwire

Abstract

We demonstrated a flexible strain sensor based on ZnSnO3 nanowires/microwires for the first time. High-resolution transmission electron microscopy indicates that the ZnSnO3 belongs to a rhombohedral structure with an R3c space group and is grown along the [001] axis. On the basis of our experimental observation and theoretical calculation, the characteristic I–V curves of ZnSnO3 revealed that our strain sensors had ultrahigh sensitivity, which is attributed to the piezopotential-modulated change in Schottky barrier height (SBH), that is, the piezotronic effect. The on/off ratio of our device is ∼587, and a gauge factor of 3740 has been demonstrated, which is 19 times higher than that of Si and three times higher than those of carbon nanotubes and ZnO nanowires.