Study On The Optical And Electrical Properties Of Zn-Based Thin Films Prepared By Sol-Gel Method

ZnO is a direct wide band gap semiconductor, which band gap is3.37eV and exction binding energy is60meV. Because of good c-axis orientation and high electric resistivity, ZnO have good photoelectric properties. Beacuse single ZnO films are instable, we can improve its performance and tune wavelength of ZnO films through the way of doping technology. Doped ZnO can be used in the area of gas detection, liquid crystal imaging, ultraviolet emission and camera technology. The intrinsic ZnO is n-type semiconductor, so the study to preparation of p-type ZnO has been a hot topic.we used a simple Sol-Gel spining coating method to preparation of ZnO transparent conducting oxide films on quartz substrates. Beacuse of pure ZnO films are not good conductivity properties, which need to doping Mg into ZnO lattice. Doping Mg can increase its emission wavelength. Through several groups of experiments,we get a optimal outcome, when the doping concentration of Mg is20at%and the average transmittance of visible range is more than90%. Furthermore, the light transmittance of films in the ultraviolet region is increasing.Through a series of measurements on the films by UV-Vis, XRD, SEM, PL and Hall, we know the films light transmittance are90%from near ultraviolet to visible light, and its have a good c-axis orientation with the|structure of hexagonal wurtzite. The grain size of films are bigger when the annealing temperature raising.In PL measurement, only the peaks of pure ZnO cane be found,which prove the Mg have been doped into the lattice of ZnO.