Temperature dependent electrical properties of pulse laser deposited Au/Ni/β-(AlGa)2O3 Schottky diode

We have demonstrated the epitaxial growth of a β-(Al_0.08Ga_0.92)₂O₃ film on a β-Ga₂O₃ (010) substrate through pulsed laser deposition. The temperature-dependent electrical characteristics of Au/Ni/β-(Al_0.08Ga_0.92)₂O₃ Schottky diodes were investigated in the temperature range of 300-573 K, using thermionic emission theory to calculate the Schottky diode parameters. The barrier height ϕ_b was found to increase, while the ideality factor n and the series resistance R_s were found to decrease with increasing temperatures. The calculated values of ϕ_b and n varied from 0.81 eV and 2.29 at 300 K to 1.02 eV and 1.65 at 573 K. The temperature-dependent I-V characteristics of the Schottky diode have shown the Gaussian distribution, yielding a mean barrier height of 1.23 eV and a standard deviation of 0.147 V, respectively. A modified Richardson plot of ln (I_s /T² )-(q²σs₂ /2 k²T² ) versus q/2kT gives ϕ_{b 0} ̄ and A* as 1.24 eV and 44.3 A cm^-2 K^-2, showing the promise of Ni/β-(AlGa)₂O₃ as a Schottky diode rectifier.