Low-frequency current pulses in a semiinsulating GaAs device

Abstract

Coherent low-frequency current pulses (3×10−3–2×10−2 Hz at room temperature) have been observed in semiinsulating (SI) GaAs with an epitaxial n-GaAs film (n) as a cathode and an evaporated metal as an anode. By measuring the potential drop across the n-SI junction, very high electric fields have been found near the junction. The periodic creation and annihilation of a space-charge barrier due to deep-lying electron traps localized at the n-SI junction qualitatively explains the prominent features of the phenomenon.