A PRIMITIVE MODEL FOR EVALUATING THE CONTRAST OF PHOTOCURRENT IMAGES OBTAINED AT THE SEMICONDUCTOR-ELECTROLYTE INTERFACE

A model is developed for interpreting the contrast observed in photocurrent images obtained using scanned illumination from a laser source. It combines current theories of carrier generation, surface-state recombination, and electron transfer processes with a primitive site-wise scanning routine to assess the effects of potential, scan rate, beam size, and incident intensity on the form of the image. The results of the model are discussed with reference to scanned photocurrent images obtained with a transparent electrolyte phase contacting n-Si, Bi, and Fe phases.