Electroreflectance and Wavelength Modulation Study of the Direct and Indirect Fundamental Transition Region of In1−xGaxP

Abstract

The direct E_o, E_o + Δ_o and indirect E_Γ−X transition energies of In_1−xGa_xP crystals are studied by electromodulation and wavelength modulation methods at 77 K and room temperature. The E_o energy at 77 K and room temperature obeys a parabolic relation as a function of composition x with a bowing parameter of b = 0.764 and 0.76 eV, respectively. The E_Γ−X energy at 77 K can be expressed by a linear x‐dependence with slope 0.072 eV. The crossover point at 77 K is determined as x_c = 0.72 ± 0.015; E_c = (2.300 − 0.003) eV. The spin‐orbit splitting Δ_o shows an upward bowing with bowing parameter −0.060 eV.