THIN SOLID FILMS, cilt.564, ss.367-374, 2014 (SCI-Expanded)
The current–voltage (I–V) characteristics of the Ni/Al0.26Ga0.74N Schottky barrier diodes (SBDs) were measured
in the temperature range of 100–310 K by the step of 10 K. The forward I–V characteristics were analyzed on
the basis of the thermionic emission theory. The characteristics of diode parameters such as the Schottky barrier
height (SBH) and the ideality factorwere investigated as a function of temperature. An experimental SBH value of
about 1.021 eVwas obtained for the Ni/Al0.26Ga0.74N SBD at 300 K. The experimental results showthat the values
of the ideality factor decreasewhile the values of the SBH increasewith increasing temperature. The temperature
dependence of the SBH was explained on the basis of a thermionic emission mechanism with the Gaussian
distribution of the SBHs due to the SBH inhomogeneities at the metal–semiconductor interface. The values of
the mean barrier height Φb0 and the standard deviation σs0 were 1.362 eV and 133 meV in the temperature
range of 210–300 K, 1.204 eV and 111 meV in the temperature range of 100–210 K, respectively. The modified
Richardson plots according to inhomogeneity of the SBHs have a good linearity in the corresponding temperature
range. The values of Richardson constant A* were found to be 31.46 Acm−2 K−2 and 33.36 Acm−2 K−2 in the
temperature ranges of 210–310 K and 100–210 K, respectively. The obtained Richardson constant values are in
good agreement with the theoretical value of 34.56 Acm−2 K−2 known for n-type Al0.26Ga0.74N.