HIGH QUANTUM EFFICIENCY SCHOTTKY DIODE PHOTODETECTOR ON THE BASE OF ULTRATHIN GAAS-ON-SI FILM

A new type of a Schottky diode photodetector based on the ultrathin (1 0 nm) low-temperature grown GaAs-on-Si heterolayer was fabricated and studied. Properties of the heterostructure and electrical characterist ics of the photodetector were determined using low-temperature photolu minescence, high-resolution transmission electron microscopy, capacita nce-voltage, current-voltage, and spectral responsivity measurements. The high responsivity of the photodetector (corresponding to external quantum efficiency of 0.8-0.9) is explained by effective carriers sepa ration in the GaAs layer and by the carrier multiplication effect at t he GaAs/Si interface. (C) 1996 American Institute of Physics.