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We report on the recent progress made toward development of a III-nitride based tunable hyperspectral detector pixel with the potential advantages of reduced hardware complexity and increased dynamic control on the detection parameters in the context of existing hyperspectral detection systems. We discuss the concept, experiments, and simulation of devices along with the different obstacles to be overcome before this technology can mature into a commercial application. [ABSTRACT FROM AUTHOR]

A reduction of edge dislocations in the GaN layer on Si substrate by almost an order of magnitude to 8.0×107/cm2 and reduction in screw dislocations by a factor greater than 4 are achieved for the film grown on the Si (111) substrate engineered to have a polycrystalline defective layer at the AlN/Si interface. The formation of a polycrystalline defective layer at the AlN/Si interface by N+ ion implantation provides substrate conditions that result in a heteroepitaxial GaN film with much improved surface morphology and better crystal quality as compared to the film grown directly on AlN/Si. A mechanism of dislocation defect reduction in the epitaxial film is given based on the detailed study of AlN/Si interfaces as well as the evolution of the AlN buffer layer in the context of this substrate engineering technique, which shows partial decoupling of the III-nitride layers from the substrate to be responsible for the improved characteristics. [ABSTRACT FROM AUTHOR]