Very high photoconductive gain of about 104–105is observed in GaAs photoconductive detectors for low photon flux density of 1015–1017photons/(cm2·s). This high gain decreases with increasing photon flux density. A model is proposed which includes carrier separation by surface band dending and surface recombination of photogenerated carriers controlled by surface barrier height. This model is shown to quantitatively explain the photon flux density dependence of both high gain and response time.
ASJC Scopus subject areas
- Physics and Astronomy(all)