Enhanced self-powered ultraviolet photoresponse of ZnO nanowires/p-Si heterojunction by selective in-situ Ga doping
Abstract
In the current work, Ga-doped ZnO nanowires are grown by employing double step chemical bath deposition (CBD) method on Si substrate for fabricating the n-Ga:ZnO nanowires/p-Si heterojunction photodiodes. The doping concentrations have been systematically varied (1%-5%) for obtaining superior photo-responsive properties. The morphology, chemical composition and crystalline nature of the grown nanowires are studied by using FESEM, EDS and XRD, respectively. The vacancies/defect states and energy bandgap are studied from CL and UV-vis spectra. The photo-electric measurements indicate that optimized Ga-doped ZnO nanowires/p-Si heterojunction provides enhanced performance in terms of photo-to-dark current ratio (>2 × of undoped), response time, responsivity (0.192 A/W) and EQE (62.7%) in self-powered mode. At zero bias, 16.6% enhancement in responsivity has been observed for optimized Ga-doped ZnO nanowires/p-Si heterojunction as compared to undoped one with a highly selective UV-A (320 nm-400 nm) spectrum.
- Publication:
-
Optical Materials
- Pub Date:
- July 2020
- DOI:
- 10.1016/j.optmat.2020.109928
- Bibcode:
- 2020OptMa.10509928S
- Keywords:
-
- ZnO nanowires/P-Si heterojunction;
- Ga-doping;
- Self-powered;
- UV-Detection