Strain-enhanced cable-type 3D UV photodetecting of ZnO nanowires on a Ni wire by coupling of piezotronics effect and pn junction

A 3D-sensitified and strain-enhanced UV wire-photodetector has been fabricated with ZnO NWs grown on an oxidized Ni wire by chemical vapor deposition method. The photoluminescence (PL) spectra of the device shows a sharp UV peak at around 380 nm and a negligible peak at around 520 nm, which proves that the as-prepared ZnO nanowires were well-crystallized. The current-voltage (I-V) and current-time (I-T) characteristics under different rotation angles of the heterojunctions show good rectifying diode behaviors and stability under different angles which make 3D detection possible. The sensitivity of the device is enhanced by strains due to piezotronic effect of ZnO nanowires. These performances of the device demonstrates a promising approach to 3D photodetecting and strain sensing and also provide a prospective application to the development of weaving single wire into fabrics technology.