Charge-Carrier Dynamics Following Pulsed Photoinjection

Abstract

The transient behavior of charge carriers generated by pulse illumination of arbitrary intensity is investigated. The configuration treated is that in which one surface of a photoinsulating sample is grounded and the other charged to an initial potential V₀ and left floating. Within the framework of the assumed model, expressions have been derived which completely describe the spatial and temporal dependence of the carrier density, electric field, and conduction current density. These expressions provide a physical picture of the charge‐carrier dynamics within the photoinsulator and allow a qualitative discussion of possible trapping effects. Solutions are also obtained for the physically observable surface potential and its time rate of change. The geometry considered here is that usually employed in electrophotographic applications of photoinsulators for information copying and image conversion devices.