Abstract

An analysis of the photocurrents produced by nonuniform illumination of a sensitive photoconductor is given. It is shown that for sensitive photoconductors in the steady state, the current density is a constant throughout the bulk of the photoconductor, under all conditions of excitation. The expression for the photocurrent density as a function of illumination and applied field is then obtained through an integration of Poisson’s equation, with a model of the photoconductor as a thin, flat slab and illumination incident perpendicular to one face. The boundary conditions take into account the existence of secondary photocurrents drawn in from the electrodes by space charge resulting from the primary excitation. It is found that large secondary photocurrents can be obtained under nonuniform excitation if the shallow electron trap density is low and electron capture cross section of hole-containing centers is low. Experimental results are reported for photocurrents in sensitive evaporated films of CdS:Ag, which satisfy the geometry requirements of the analysis.

© 1963 Optical Society of America

Erratum: Nonuniformly Excited Photoconductivity in Sensitive Photoconductors

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J. Opt. Soc. Am. 54(1) 133_1-133 (1964)

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