Temperature-dependent electrical transport properties of (Au/Ni)/n-GaN Schottky barrier diodes
The temperature-dependent electrical properties of (Au/Ni)n-GaN Schottky barrier diodes (SBDs)have been investigated in the wide temperature range of 40-400 K. The analysis of the main electrical characteristics such as zero-bias barrier height (Phi(B0)), ideality factor (n) and series resistance (R-s) were found strongly temperature dependent. Such behavior is attributed to barrier inhomogeneities by assuming a Gaussian distribution (GD) of barrier heights (BHs) at the interface. It is evident that the diode parameters such as zero-bias barrier height increases and the ideality factor decreases with increasing temperature. The values of series resistance that are obtained from Cheung's method are decreasing with increasing temperature. The temperature dependence of Schottky barrier height (SBD) and ideality factor (n) are explained by invoking three sets of Gaussian distribution of (SBH) in the temperature ranges of 280-400 K. 120-260 K and 40-100 K. respectively. (Au/Ni)/n-GaN Schottky barrier diode have been shown a Gaussian distribution giving mean BHs (Phi) over bar (B0)) of 1.167, 0.652 and 0.356 eV and standard deviation sigma(s) of 0.178, 0.087 and 0.133 V for the three temperature regions. A modified In(I-0/T-2) q(2)sigma(2)/2k(2)T(2) vs. 1/kT plot have given (Phi) over bar (B0) and A* as 1.173 eV and 34.750 A/cm(2) K-2, 0.671 eV and 26293 A/cm(2) K-2, 0.354 eV and 10.199 A/cm(2) K-2, respectively. (C) 2014 Elsevier B.V. All rights reserved.