Temperature Dependence of the Phonons of Bulk AlN

Micro-Raman scattering measurements were performed on bulk wurtzite AlN crystals over a temperature range from 10 K to 1275 K. The temperature dependence of the frequency of the AlN phonons follows an empirical relationship previously introduced for diamond. A temperature-induced frequency shift of the E2phonon of -(2.22±0.02)×10-2cm-1/K was determined for high temperatures, which is similar to values reported for bulk GaN. The results provide the basis for the non-invasive monitoring of the temperature of (Al,Ga)N by Raman scattering.