Elastic and thermal properties of strain-tailored air-gap heterostructures

The temperature-dependent expansion coefficient α(T) in strain-tailored semiconductor air-gap heterostructures (AGHs) has be measured via static x-ray diffraction (XRD). Results show significant deviation from comparable thin-film systems and point to a structural blocking of high-frequency LA and optical phonon modes. Time-dependent XRD measurements reveal different thermal transport regimes on picosecond and nanosecond timescales.