A numerical method for determining photoconductor mobilities

A photoconductor\u27s mobility is a measure of the speed at which electrons migrate through the material under the influence of an electric field. The mobility determines how long a packet of charge takes to go through the photoconductor. It also determines how much and in what manner the E-field changes during the packet transit. The problem in which we are interested is inferring the mobility of a photoconductor from time-of-f light measurements, that is, from measurements of the current produced per unit time by a known charge packet. Mathematically, the problem is an initial-boundary value problem for a nonlinear, non-local, hyperbolic conservation law that characterizes the E-field in the photoconductor. In this paper, we discuss the mathematical formulation of this problem, its solution using the method of characteristics, and the application of the solution to the problem of inferring mobilities