Characteristics of semi-insulating GaAs photoconductive detectors under steady state illumination

Graduation date: 1987The optical and electrical characteristics of semi-insulating GaAs photoconductive detectors made with ohmic and Schottky contacts are studied in this thesis. Current - voltage measurements are made both in the dark and under varying power levels of HeNe laser (6328 Å) illumination. DC photocurrent gain is then calculated as a function of bias voltage based on the experimental data. Temperature variations of spectral response are also measured. An operating mechanism of the ohmic contact detector is proposed. A simplified model is used to calculate the initial current versus voltage characteristics of the Schottky contact detectors. The calculated curves agree qualitatively with the experimental results