Photo-emf in Parabolic Graded-Gap Semiconductors

Abstract

Subject classification: 72.40.+w; S7.15We have calculated the photo-emf in square profile graded band-gap semiconductor structures under local illumination. It is shown that the photo-emf is a linear function of the position of a light strip on the photosensitive surface and it changes the sign when the light strip passes across the center of the structure. The coordinate sensitivity of Ga 1--x Al x As graded-gap structure can be larger than 1.4 Â 10 6 V/Wm.