The innovative proposed here is the development of a new type of radiation-discriminating, long-wavelength infrared (lwir) detector based on impurity-band-conduction (ibc). The new configuration enables one to discriminate between gamma-ray and lwir-induced events. Past use of ibc photodetectors has shown that injected dark current from the contacts is a major problem limiting their use. For the ibc configuration of interet here, the use of a bias-dependent superlattice (sl) tunneling structure is proposed is the exploitation of the fact that there is a critical bias below which ibc is essentially random and above which ibc is parallel to the electric field. This makes possible the storage of lwir-generated ionized donors and also the read-out of gamma-ray generated electrons and holes. The ionized donors areperiodically read-out and this forms the basis of lwir detection. Phase i would be a feasibility study, including the determination of the optimum device design, operating parameters, and expected current vs. Bias behavior in the presence of gamma-rays. This phase ii goal is the successful fabrication and testing of this device.
