Ultraviolet photodetectors with Ga-doped ZnO nanosheets structure

In this study, Ga-doped ZnO (GZO) nanosheets were grown on a glass substrate by using aqueous solution method. A GZO nanosheet metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) was also fabricated. The average length and diameter of the GZO nanosheets were 2.06 mu m and approximately 20 nm, respectively. The EDX spectrum determined that the Ga-doped sample contains approximately 1.35% at%. The UV-to-visible rejection ratio of the device is approximately 42 when biased at 1 V, and the fabricated UV PD is visible-blind with a sharp cutoff at 370 nm. The photo-current and dark-current constant ratio of the fabricated PD was approximately 14193 when biased at 1 V. The transient time constants measured during the rise time and fall time were 2.45 s and 4.0 s, respectively. (C) 2015 Elsevier B.V. All rights reserved.