A two-dimensional analysis of transfer in a charge injection infrared sensor

The results of an examination of numerical models for the functioning of IR charge injection devices (CIDs) are presented, with attention given to operation at low control voltages at the electrodes. One model covers a sole electrode in an equation relating the storage to transfer, and it is shown that with an initial charge of 1.5 V, the transfer time depends on the initial charge. A second model is presented for a CID with two coplanar electrodes separated by a variable gap. The field between the electrodes is calculated using the two-dimensional Green's equation, while the auto-induced field effect is modeled by the one-dimensional Poisson equation. The most accurate model is found to be a two-dimensional model for calculating the time-dependent behavior of the depletion zone and the surface potential, covering the entire domain of solution of the Green equations. It is found that the distance between the electrodes in a coplanar device must be one micron or more for the cell to function correctly.