Electromodulation reflectance of low temperature grown GaAs

Abstract
We have studied low temperature grown GaAs by electromodulation reflectance spectroscopy for growth temperatures between 200 and 320 °C. The reflectance spectra can be observed only when the concentration of the arsenic antisite defect is lower than 3.4×10 19 cm −3 . The absence of the signal for a rich defect sample is related to the short carrier lifetime and surface depletion width. The transition energies of E 0 and E 1 are found to increase with the decrease of the growth temperatures. The increase of the transition energies is attributed to lattice mismatch and deviation of the stoichiometry.