Effect of sulphur atoms on surface current in gaas P-n junctions

Abstract

Sulphur atoms passivation of GaAs surface and its influence on I-V characteristics of forward and reverse currents, photocurrent spectrum, and sensitivity of GaAs p-n structures as gas sensors were studied. The passivation reduces the excess forward current and reverse current in p-n junctions, enhances the photosensitivity in the spectral region of strong absorption, substantially increases the sensitivity to ammonia vapors. All these effects are explained, taking into account lowering of the surface states density as a result of sulphur atoms deposition.