Temperature Dependence of the Wavelength-Modulation Spectra of GaAs

Wavelength-modulation spectroscopy is used to obtain the temperature dependence of the reflectivity spectrum for GaAs. Results are given in the regions of the $E_1$ doublet and the major $E_2$ peak at 5, 80, 150, 225, and 300°K. The theoretical temperature dependence in these regions is obtained through use of Debye-Waller factors and thermal expansion coefficients in an empirical pseudopotential calculation of the ${\Lambda }_3-{\Lambda }_1$ and ${\Sigma }_2-{\Sigma }_1$ energy splittings.