Investigation of high-quality GaAs:In layers grown by molecular-beam epitaxy

Abstract

Indium-doped GaAs layers are investigated by low-field Hall-effect, photoluminescence, deep-level transient spectroscopy, current-voltage, and capacitance-voltage measurements for the In value providing the best layer quality. The In doping concentrations were 20 ppm to 25%. The growth was made in the temperature range 530–575 °C. Layers grown at higher temperatures show increased carrier mobility, sharper photoluminescence peaks, as well as a lower concentration of deep levels. The investigation suggests that the In concentration should be between 100 and 5000 ppm and the growth temperature above 550 °C to provide the best quality of the layer.