Characterization of interface defects in GaAs-GaAlAs superlattices

Abstract

Capacitance transients in a 20-20 Å GaAs-Ga0.7 Al0.3As n-type (3×1016 cm−3) Si-doped superlattice have been performed. In the temperature range 50–100 K, a logarithmic time decay is observed. We attribute this time decay to the existence of a continuum of deep levels in the fundamental gap of the superlattice, related to electron traps located at the GaAs-GaAlAs interfaces.