Structure and Property of Ga2(Nxo1-X)3 Films Synthesized by Sol-Gel Method

Abstract

Ga2O3 exhibits great potential for applications in solar-blind ultraviolet photodetector, high-power electronic devices and solid-state light-emitting due to its ultra-wide bandgap and high Baligas figure of merit. Here, Ga2(NxO1-x)3 films with varied nitrogen contents were prepared by the sol-gel technique. The structural and optical properties of Ga2(NxO1-x)3 films were examined in detail by X-ray diffraction (XRD), Scanning electron microscope-Energy Dispersive Spectrometer (SEM-EDS), Fourier Transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Ultraviolet and Visible spectrophotometer (UV-VIS), Photo-luminescence spectroscopy (PL). And heterojunctions consisting of Ga2(NxO1-x)3 films and n-type silicon were built. XRD analysis reveals that nitrogen doping contributes for growth of greater crystallines and SEM-EDS measurements confirm that the monoclinic crystal structure of Ga2(NxO1-x)3 is maintained to doping level of 3.26wt%; FTIR information indicates that nitrogen prefers to substitute for the O1 and O2 site of Ga2O3; XPS offers evidence that nitrogen tends to occupy oxygen vacancies and generate more gallium vacancies; UV-VIS shows that impurity defects appear on valence band, and the absorption position undergoes a red shift with nitrogen above 1.32wt%; PL shows Ga2(NxO1-x)3 films can emit light of various colors under excitation at 325nm, and the acceptor level is at 1.63eV~2eV above the valence band; The conductivity of Ga2(NxO1-x)3 films is changed from n-type to p-type when nitrogen-doping is 0.96 wt% and the I-V curve composed of Ga2(NxO1-x)3 and Ga2O3 shows PDCR=43 under the 254nm light. Therefore, the development of nitrogen-doped β-Ga2O3 has potential opportunities for applications in photoelectric devices.

Keywords: Ga2O3, N-doped, Sol-gel, Photoluminescence, I-V characteristics