Microwave detection with n -GaAs/ N -GaAlAs heterojunctions

n-GaAs/N-GaAlAs heterojunctions have been grown on highly doped (100) GaAs substrates by l.p.e. Microwave detector diodes made of these layers have been operated successfully for the first time at frequencies up to 18 GHz. The open-circuit voltage sensitivity is comparable with commercially available Schottky-barrier diodes. Their high-frequency performance as well as the observed potential distributions measured across the junction indicate that minority-carrier effects are absent.