Temperature dependence of local vibrational mode optical absorption for carbon acceptors in GaAs

Abstract
The local vibrational mode (LVM) absorption band due to CAs in GaAs is reported for three semi-insulating samples at room temperature and for T<77 K. Data obtained by Fourier transform infrared spectroscopy at resolution values from 1.0 to 0.1 cm−1 indicate that the area of the carbon LVM band increases by ∼60% upon cooling from room temperature, a substantially larger increase than some accounts have suggested. Our recommended value for the calibration factor f in going from LVM band area to carbon concentration is fRT≂1.6fLT ≂(13±3)×1015 cm−1.