Mean barrier height of Pd Schottky contacts on ZnO thin films

We have investigated the temperature dependence of the barrier height of high-quality Pd Schottky contacts on (0001)-oriented ZnO thin films by temperature-dependent current-voltage and capacitance-voltage (CV) measurements. The films have been grown by pulsed-laser deposition. The effective Schottky barrier height Phi(B,eff) deduced from the current-voltage measurements was evaluated by considering a Gaussian barrier height distribution with a standard deviation sigma around a mean barrier height Phi(B,m). We determined Phi(B,m)=(1.16 +/- 0.04) eV which agrees well with the value of 1.14 eV determined by CV measurements. The standard deviation is determined to be (134 +/- 10) meV. (c) 2006 American Institute of Physics.