Highly efficient and ultra-fast visible-blind ultra-violet detectors

A two-step molecular beam epitaxy growth approach, which enjoys the advantage:: of being wet-chemical-etching free, was developed to fabricate: a ZnSTe-based Schottky barrier photovoltaic ultra-violet (UV) detector array on GaP(100). Visible blind and UV sensitive response were achieved with peak responsivity of 1.23 A/W and 1.2 x 10(6) V/W at 320 nm. Through the measurement of the photovoltage output as a function of incident photon power, the build-in potential of the detector was determined to be 1.7 V. Temporal response measurement of the device thews that the photocurrent decays with a time constant as fast as 1.2 ns, limited aparently by the RC time constant of the detect or structure.