Comparison of the 3ω method and time-domain thermoreflectance for measurements of the cross-plane thermal conductivity of epitaxial semiconductors

The 3 omega technique and time-domain thermoreflectance (TDTR) are two experimental methods capable of measuring the cross-plane thermal conductivity of thin films. We compare the cross-plane thermal conductivity measured by the 3 omega method and TDTR on epitaxial (In0.52Al0.48)(x)(In0.53Ga0.47)(1-x)As alloy layers with embedded ErAs nanoparticles. Thermal conductivities measured by TDTR at low modulation frequencies (similar to 1 MHz) are typically in good agreement with thermal conductivities measured by the 3 omega method. We discuss the accuracy and limitations of both methods and provide guidelines for estimating uncertainties for each approach.