IR material research at the Army Research Laboratory

Abstract

Research on Mercury Cadmium Telluride (HgCdTe or MCT) and group III-V based infrared materials is being conducted for the development of advanced, especially large area IR detector and focal plane arrays. The focus of this research has been on materials for Quantum Well Infrared Photo Detectors (QWIPs), Sb based type II superlattice detectors, Silicon based substrates for MCT detectors and MCT detectors with higher operating temperature. Recently research has been initiated in dilute Nitride materials. To improve the quantum efficiency, reproducibility and operating temperature of the QWIP detectors, a corrugated design has been implemented. For superlattice detectors, focal plane arrays for the MWIR spectral band have been successfully demonstrated and good image quality has been obtained. Current efforts are concentrated on achieving high quality materials and passivation techniques for the LWIR spectral band. A recently initiated effort on dilute Nitride materials holds the premise to obtain high quality direct bandgap detectors with III-V materials. For MCT detectors on Si based substrates MWIR detectors have been demonstrated with high quality, but for LWIR detector arrays of sufficient low defect densities have not been obtained on a consistent basis. Recent efforts showing promising results will be discussed.