Characterization of low-temperature GaAs by galvanomagnetic an photoluminescence measurements

Electrical and photoluminescence (PL) properties of low-temperature (LT)-GaAs molecular beam epitaxy (MBE) layers grown at 400 and 420 °C were studied. Results indicate that a boundary between the nonstoichiometric and conventional MBE growth lies near the growth temperature of 400 °C. This transition is indicated by the conductivity ratio σband/σhop, which is close to 1 with a slight domination of hopping component. Annealing at temperature of 590 °C for 10 min results in a shift of the deep level position from a value of 0.68 eV by about 50–76 meV in direction to the valence band. This change is revealed using both electrical and PL measurements.