Flux Method for the Field Dependent Transport through Multilayer Devices

摘要

A flux method of treating the one dimensional steady state transport problem of excess charged carriers, created by the generating sources, is analyzed for the multilayer devices in the presence of a nonuniform electric field. General analytical expressions for the forward and backward fluxes of excess carriers at any arbitrary boundary of the multilayer device are derived in terms of the reflection and transmission coefficients of the individual layers and boundaries. For an isolated layer, these coefficients are obtained in analytical form in terms of backscattering and absorption probabilities of charged carriers and the layer's thickness. In a multilayer device, the reflection and transmission coefficients of any layer or boundary get affected due to the presence of other layers and boundaries. Therefore the effective reflection and transmission coefficients of layers and boundaries are calculated in terms of reflection and transmission coefficients of the isolated layers and boundaries. These effective coefficients are then used to obtain the reflection and transmission coefficients of the entire multilayer device. As an application of this general analysis, a simple example of a multilayer device consisting of only two layers is worked out. The results are shown to reduce to those obtained by other calculations in appropriate limiting cases.