Date of Original Version
Copyright 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article may be found at http://dx.doi.org/10.1063/1.4718354
Abstract or Description
Thermal conductivities (k) of the individual layers of a GaN-based light emitting diode(LED) were measured along  using the 3-omega method from 100-400 K. Base layers of AlN,GaN, and InGaN,grown by organometallic vapor phase epitaxy on SiC, have effective kmuch lower than bulk values. The 100 nm thick AlN layer has k = 0.93 ± 0.16 W/mK at 300 K, which is suppressed >100 times relative to bulk AlN. Transmission electron microscope images revealed high dislocation densities (4 × 1010 cm−2) within AlN and a severely defective AlN-SiC interface that cause additional phonon scattering. Resultant thermal resistances degrade LED performance and lifetime making layer-by-layer k, a critical design metric for LEDs.
Applied Physics Letters, 100, 201106.