Affiliation:
1. Materials Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology, Xi’an 710021,
China
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:
Ga2O3 NWs 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.
Funder
National Natural Science Foundation of China
Publisher
Bentham Science Publishers Ltd.
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