Effects of annealing and Nb doping on the electrical properties of p-Si/n-β-Ga 2 O 3 :Nb heterojunction

p-Si/n-β-Ga2O3:Nb heterojunctions were fabricated by RF magnetron sputtering of β-Ga2O3:Nb layers on the p-Si substrates. The effects of annealing and Nb doping on the properties of heterojunctions were studied. The crystallinity of the β-Ga2O3:Nb film was enhanced by annealing, which also improved the electrical properties of the heterojunctions. The Nb doping greatly affected the I–V characteristics of annealed heterojunctions. The ideality factor was calculated by performing plots from the forward bias I–V characteristics. The charge transport properties of the heterojunction were discussed. The activation energy of β-Ga2O3:Nb films were estimated based on the temperature dependence of resistance.