Anomalous temperature dependence of the electrical conductivity in metal/beta-Ga2O3/n-Si structures

Electrical characteristics of Metal/β-Ga2O3/n-Si structures with pure β-Ga2O3, Ti – and Cr – doped β-Ga2O3 films have been investigated. For all samples, regardless of the dopant type, a current decrease with the temperature increase is observed both at forward and reverse biases. The anomalous temperature dependencies are explained by the presence of traps located in a certain energy range near the bottom of the conduction band Ec. When the positive potential is applied to the electrode on the side of gallium oxide, the current-voltage characteristics are described as space charge limited current in the presence of energy distributed traps. In the case of a negative potential applied to the electrode on the side of gallium oxide, the reverse currents are due to the hopping conduction to the nearest neighboring state unoccupied by the electron.