Thermal conductivity of GaN crystals in 4.2–300 K range

Autor: Stanislaw Krukowski, Tadeusz Suski, T. Paszkiewicz, Izabella Grzegory, Andrzej Jeżowski, B. A. Danilchenko, Michal Bockowski
Rok vydání: 2003
Předmět:
Zdroj: Solid State Communications. 128:69-73
ISSN: 0038-1098
Popis: Results of measurements of thermal conductivity of bulk GaN crystals in the temperature interval 4.2 – 300 K are reported. Experiments were performed on two types of single GaN crystals grown under high-pressure: highly conducting n-type sample and on a highly resistive sample compensated by magnesium doping. For n-GaN crystals, the highest thermal conductivity kmax is equal to 1600 W/m K at Tmax ¼ 45 K; and k . 220 W/m K at 300 K. Our analysis indicates that for the best n-GaN crystal and for T $ Tmax; the contribution of Umklapp phonon scattering processes dominate whereas for other samples scattering of phonons by point mass defects represents the main contribution. The dependence of kðTÞ is used to reveal possible mechanisms of thermal resistance of GaN crystals at temperatures Tmax: Our thermal conductivity measurements yields Debye’s temperature uD < 400 K: q 2003 Elsevier Ltd. All rights reserved.
Databáze: OpenAIRE