Temperature-dependent electrical transport properties of (Au/Ni)/n-GaN Schottky barrier diodes

•In this work, an attempt is made to investigate the detailed electrical properties of (Au/Ni)/n-GaN Schottky barrier diodes (SBDs) in a wide temperature range 40–400 K with a temperature step of 20 K by using the forward bias I–V measurements.•Barrier height (ΦB0), ideality factor (n) and series resistance (Rs) of the device are extracted from the forward bias I–V measurements.•The series resistance (Rs) parameter determined from forward bias I–V characteristics using Cheung and Cheung׳s method.

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 (ΦB0), ideality factor (n) and series resistance (Rs) 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 (Φ¯B0) of 1.167, 0.652 and 0.356 eV and standard deviation σs of 0.178, 0.087 and 0.133 V for the three temperature regions. A modified ln(I0/T2)−q2σ2/2k2T2 vs. 1/kT   plot have given Φ¯B0 and A⁎ as 1.173 eV and 34.750 A/cm2 K2, 0.671 eV and 26.293 A/cm2 K2, 0.354 eV and 10.199 A/cm2 K2, respectively.

Graphical abstractForward bias I-V characteristics of (Au/Ni)/n-GaN SBD at various temperatures.Figure optionsDownload full-size imageDownload as PowerPoint slide