Title:CVD Approach to a Single Gallium Oxide Nanowire for Solar-blind UV
Detector
Volume: 3
Issue: 1
Author(s): Song Liu, Shufang Ma*, Xin Huang, Guang Hui Wang, Bo Liu, Dou Wang, Hui Can Ou Yang, Chao Ming Xu, Sheng Wei Liu, Guo Dong Wei, Bin Han, Xiao Dong Hao and Bing She Xu
Affiliation:
- Materials Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi’an 710021,
China
Keywords:
CVD, β-Ga2O3 nanowires, growth control, solar-blind UV photodetectors, detection performance, external quantum efficiency.
Abstract:
Aims: Finding a simple, energy-saving and low-cost synthesis method to process gallium
oxide nanowires by CVD for solar-blind detector.
Background: Due to a bandgap of 4.5 ~ 4.9 eV and a high breakdown field strength of 8 MV/cm,
gallium oxide (Ga2O3) has great application prospects in solar blind ultraviolet detection and highpower
devices. Notably, Ga2O3 NWs are currently the key research objects of solar-blind UV detection
materials because of the characteristics of efficient photocarrier separation and collection, and
the bandgap width perfectly matches the energy of deep ultraviolet photons.
Objective: To find a simple method to synthesize Ga2O3 nanowire with smooth surface and uniform
diameter, and the prepared single gallium oxide nanowire UV detector has high photoelectric conversion
efficiency.
Methods: Ga2O3NWs are prepared on the SiO2/Si substrate by chemical vapor deposition (CVD)
approach at low reaction temperature with gold particles serving as the catalyst and gallium arsenide
(GaAs) as a gallium source.
Results: X-ray diffraction and Raman spectroscopy characterization indicate the crystal structure of
NWs is β-Ga2O3, and scanning electron microscope (SEM) characterization proves that the NWs
have a uniform diameter and smooth surface. Moreover, the high-resolution transmission electron
microscopy (HRTEM) characterization shows that the material had high crystal quality. Moreover,
the photoconductive solar-blind UV detector with a single Ga2O3 NW is prepared, showing the excellent
performance of the high responsivity and external quantum efficiency.
Conclusion: The effects of growth temperature and the size of gold catalyst on the morphology of
β-Ga2O3 NWs have been investigated. The results show that with the reaction temperature is 625 °C
and the diameter of Au catalyst is about 30~50 nm, it is more conducive to the formation of NMs
with crystal structure, smooth surface and uniform diameter. The performance of the solar-blind UV
photodetector shows that the device has higher sensitivity (R = 149.82 A/W), external quantum efficiency
(EQE = 73206%), and response rate τrise = 0.66 s, and τdown = 0.45 s.
