Photogeneration effects in amorphous selenium.

We have found that the rate of photogeneration depends directly on the electric field applied across an evaporated film of amorphous selenium. By using a technique based on time resolving the transport of free carriers across the film, we can separate bulk trapping losses from a supply limitation in the optical generation region. Experimental results are also presented that can be used to eliminate conventional recombination effects in the optical absorption region. The wavelength and electric field dependence of the photosensitivity are directly related to the mechanism of photogeneration.