Thermal conductivity of bulk GaN single crystals

We have measured thermal conductivity, kappa, in the wide temperature range 4-300 K of GaN bulk single crystals grown by high-pressure, high-temperature synthesis. Obtained results (1600 W/Km at 45 K) are the highest kappa values reported on GaN material. At the room temperature kappa is about 210 W/Km. The contributions to the GaN thermal resistance of Umklapp process, mass point defects as well as phonon scattering on dislocations and sample boundary are discussed. (C) 2003 Elsevier Science B.V. All rights reserved.