Study on the structural, optical and electrical properties of N-doped Ga2O3 films synthesized by sol-gel method

Ga 2 O 3 exhibits great potential for applications in solar-blind ultraviolet photo detector , high-power electronic devices and solid-state light-emitting due to its ultra-wide band gap and high Baliga figure of merit. Here, Ga 2 (N x O 1-x ) 3 films with varied nitrogen contents were prepared by the sol-gel technique. XRD analysis reveals that nitrogen doping contributes for growth of greater crystalline and SEM-EDS measurements confirm that the monoclinic crystal structure of Ga 2 (N x O 1-x ) 3 is maintained to doping level of 3.26wt%; FTIR information indicates that nitrogen prefers to substitute for the O 1 and O 2 site of Ga 2 O 3 ; XPS offers evidence that nitrogen tends to occupy oxygen vacancies and generate more gallium vacancies; UV-VIS shows that impurity defects appear above valence band , and the absorption position undergoes a red shift with nitrogen above 1.32wt%; PL shows Ga 2 (N x O 1-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 Ga 2 (N x O 1-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 Ga 2 (N x O 1-x ) 3 and Ga 2 O 3 shows PDCR = 43 under the 254nm light. Therefore, the development of nitrogen-doped β-Ga 2 O 3 has potential opportunities for applications in photoelectric devices.