Space-charge-limited conduction in Si n– i–n homojunction far-infrared detectors

An analytic model is presented to describe the space-charge-limited ~SCL! conduction in Si homojunction interfacial work-function internal photoemission far-infrared detectors. The basic detector unit is a thin n– i–n structure, which is operated at low temperatures and characterized by an interfacial work function at the n– i interface. The unique aspects of this case lead to simple analytic expressions for all variables of interest. The barrier shape and free-carrier concentration distribution in the i layer, and their dependence on the applied bias, i layer thickness, and compensating acceptor concentration, are calculated. The SCL current– voltage characteristic is also investigated as a function of i layer parameters. The results obtained are useful for the IR detector design and performance optimization. © 1996 American Institute of Physics. @S0021-8979~96!01708-8#