Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2012 · 11 citations · 0 references
EngineeringMaterials EngineeringMaterials ScienceOptoelectronicsSemiconductor DevicesSemiconductor MaterialsDetector TechnologyOptical Properties Of MaterialsOptical Properties Of SemiconductorsOptoelectronic MaterialsSemiconductor DetectorsSemiconductor Device MaterialsBoron Nitride DetectorsCutoff FrequencyDetector MaterialsMid-infrared MaterialsPhotodetector MaterialsRadiation Detector MaterialsThin-film Detectors
In InAs<sub>1-x</sub>Sb<sub>x</sub> material alloy composition was adjusted to achieve 200K cutoff wavelengths in the 5 μm range. Reflectance was minimized and absorption in the InAs<sub>1-x</sub>Sb<sub>x</sub> material maximized by the use of pyramid shaped structures fabricated in the InAs<sub>1-x</sub>Sb<sub>x</sub> material which function as an AR coating. Compound-barrier (CB) detectors were fabricated and tested for optical response and dark current density versus bias measurements were acquired as a function of temperature. For 5 μm cutoff detectors, QE is high, ~ 75 % between 4.0 μm and 4.6 μm and > 80 % between 2.0 μand 4.0 μm, demonstrating the efficacy of the pyramids as photon trap structures and as a replacement for multi-layer AR-coatings. J<sub>dark</sub> in the low 10<sup>-3</sup> A/cm<sup>2</sup> range at 200 K and low 10<sup>-5</sup> A/cm<sup>2</sup> range at 150 K was measured at the bias at which the QE peaked.