We report on the Raman analysis of wurtzite single-crystalline bulk AlN under hydrostatic pressures up to 10 GPa. The pressure dependence of the AlN phonon frequencies was investigated. Mode Grüneisen parameters of 1.39, 1.57, 1.71, 0.93, and 1.26 were determined for the A1 (TO), E1(TO), E2 (high), A1 (LO), and the quasi-longitudinal optical phonons, respectively. Recent theoretical calculations underestimate the pressure-induced frequency shift of the AlN phonons by about 20%-30%. Mode Grüneisen parameters of AlN were compared to those of GaN.
Bibliographical notePublisher: American Institute of Physics