Temperature dependence of the thermal diffusivity of GaAs in the 100-305 K range measured by the pulsed photothermal displacement technique

Abstract

We have measured the variation of the value of the thermal diffusivity of semi-insulating GaAs in the 100-305 K range. The method used is the pulsed photothermal displacement technique. This is a noncontact technique, and the value of the thermal diffusivity is derived from the temporal evolution of the signal rather than its amplitude. This makes the technique less susceptible to uncertainties. We find that the temperature dependence of the thermal conductivity of semi-insulating GaAs follows a power law as T-1.62, in disagreement with results obtained previously. Possible reasons for the deviation within this very important intermediate temperature range are discussed. © 1999 American Institute of Physics.