Effect of elevated temperature on optical properties of Al-doped polycrystalline ZnO films

Al doping of ZnO thin films by ion implantation and subsequent annealing was tested. A combination of Drude term with Tanguy oscillator (excitonic effects) is shown to be an appropriate parameterization of dielectric function of highly doped ZnO. The free electron density values obtained by spectroscopic ellipsometry analysis are in good agreement with those determined by Hall effect measurements.