The influence of point defects on the thermal conductivity of AlN crystals
Abstract
The average bulk thermal conductivity of free-standing physical vapor transport and hydride vapor phase epitaxy single crystal AlN samples with different impurity concentrations is analyzed using the 3ω method in the temperature range of 30–325 K. AlN wafers grown by physical vapor transport show significant variation in thermal conductivity at room temperature with values ranging between 268 W/m K and 339 W/m K. AlN crystals grown by hydride vapor phase epitaxy yield values between 298 W/m K and 341 W/m K at room temperature, suggesting that the same fundamental mechanisms limit the thermal conductivity of AlN grown by both techniques. All samples in this work show phonon resonance behavior resulting from incorporated point defects. Samples shown by optical analysis to contain carbon-silicon complexes exhibit higher thermal conductivity above 100 K. Phonon scattering by point defects is determined to be the main limiting factor for thermal conductivity of AlN within the investigated temperature range.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 11, 2018
- Source ID
- 10.1063/1.5028141
Entities
People
- Alexander Franke
- Andrew Klump
- Biplab Sarkar
- C. Hartmann
- Dorian Alden
- Matthias Bickermann
- Qiang Guo
- Ramón Collazo
- Robert Rounds
- Ronny Kirste
- Toru Nagashima
- Yoshinao Kumagai
- Zlatko Sitar
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- Japan Society for the Promotion of Science
- Leibniz Institute for Crystal Growth
- National Science Foundation
- North Carolina State University
- Tokuyama Corporation
- Tokyo University of Agriculture and Technology
- United States Department of Energy