Optical properties of AlN and GaN in elevated temperatures

Deep ultraviolet photoluminescence spectroscopy has been employed to study the optical transitions in AlN and GaN epilayers at temperatures from 10 to 800K, from which the parameters that describe the temperature variation of the energy band gap (α and β or aB and θ) and linewidth broadening have been obtained. These parameters are compared with the previously reported values in AlN and GaN obtained by different methods in narrower temperature ranges. Our experimental results demonstrate that the broader temperature range of measurements is necessary to obtain accurate values of these parameters, particularly for AlN. These results, together with other well-known physical properties of AlN, may expand future prospects for the application of III-nitride materials.