Experimental and theoretical investigations on temperature and voltage dependence of an Au/AZO thin-film Schottky diode

In this work, aluminum-doped zinc oxide (AZO) thin films were deposited by DC sputtering on a glass substrate at a typical sputtering power. It was observed that the AZO structure changes on the ZnO crystalline structure. The measurement of the transparency spectrum on the AZO films shows an optical bandgap about 4.3 eV, which the Al doping into ZnO structure pronounced width localized states by Urbach energy that was 0.42 eV. Moreover, the experimental results on the electrical properties of AZO/Au thin film were evaluated at different temperatures by four-point probe. Also, a simulation analysis on the electrical parameters of the Schottky Au/AZO junction has been done. Our calculation is based on the thermionic emission theory, in which by fitting the numerical results with the experimental current–voltage measurements, the barrier height, ideality factor and saturation current have been obtained. Our result confirmed excellent rectifying characteristics. The extracted result may be useful in designing nanoelectronic devices.