Effect of dopant concentration and crystalline structure on the absorption edge in ZnO:Y films

We study the crystalline structure and absorption spectra for zinc oxide films with different levels of yttrium doping. The are deposited on glass substrates, using radio-frequency magnetron sputtering. estimate concentration free charge carriers show that 'blue' shift fundamental edge in ZnO:Y increasing doping level (up to 4.7 wt. %) is explained by Burstein-Moss effect. At higher concentrations yttrium, behaviour described a known empirical Urbach rule.