Hydrothermal growth and ultraviolet sensing performance of well-aligned Ga-doped ZnO nanowire arrays.

Herein, gallium (Ga)-doped zinc oxide (ZnO) nanowire arrays (GZNWAs) with different Ga doping concentrations (Ga/Zn = 0–4 atom%) were grown on the interdigital patterned fluoro-doped tin oxide glass substrates by a hydrothermal technique, their crystalline structure, morphology and ultraviolet (UV) sensing performance were focused on investigating. The results showed that all the as-grown samples were hexagonal wurtzite structure of ZnO. When the Ga doping concentration was below 4%, well-aligned GZNWAs were achieved. Furthermore, five UV photodetectors (PDs) were prepared using the GZNWAs as photoactive layers, all the devices were found to be excellent responses towards 365 nm light. Among these devices, the GZNWAs UV PD (1% Ga) maintained the optimal performance, its responsivity, sensitivity, detectivity, external quantum efficiency, response time and decay time were 72.8 A/W at 5 V, 747.8 at 0 V, 5.5 × 1012 Jones, 2.5 × 104%, 10.6 s and 45.6 s, respectively. The photocurrents of all the Ga-doped ZnO nanowire arrays ultraviolet photodetectors with different Ga doping concentrations (Ga/Zn = 0–4 atom%) can be reproducibly switched from the 'ON' state to the 'OFF' state with a stable state by periodically turning UV light on and off under 71 μW/cm2 365 nm light irradiation at 3 V bias. [Display omitted] • Well-aligned GZNWAs with different Ga doping concentrations were grown by a facile hydrothermal technique. • Five low-cost GZNWAs UV PDs with different Ga doping concentrations were fabricated. • The performances of all the GZNWAs UV PDs were investigated in detail. • The GZNWAs UV PD (1% Ga) had the optimal performance. [ABSTRACT FROM AUTHOR]