A study of temperature dependent current-voltage (I-V-T) characteristics in Ni/sol-gel β-Ga2O3/n-GaN structure

beta-Ga2O3 thin films were grown on n-type GaN substrates using the sol-gel method. The forward-biased temperature dependent current-voltage (I-V-T) characteristics of Ni/beta-Ga2O3/GaN structure have been investigated in the temperature range of 298-473 K. The apparent barrier height () increased while the ideality factor (n) decreased with the increase in temperature. Such a temperature dependent behavior of and n was explained by the inhomogeneity of , which obeyed Gaussian distribution with zero-bias mean barrier height () of 1.02 +/- 0.02 eV and standard deviation () of 153 +/- 0.04 mV. Subsequently, and Richardson constant A (*) were obtained from the slope and intercept of the modified Richardson plot as 0.99 +/- 0.01 e V and 67.2 A cm(-2) K-2, respectively. The obtained from the modified Richardson plot was in good agreement with the theoretical value calculated from the work function of Ni and electron affinity of beta-Ga2O3. The I-V-T characteristics of Ni/beta-Ga2O3/GaN MOS structures can be successfully explained by the thermionic emission theory with a single Gaussian distribution of the barrier height.