Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2003 · 22 citations · 0 references
EngineeringElectrical EngineeringMaterials ScienceOptoelectronicsSemiconductor DevicesSemiconductor MaterialsDetector TechnologyPhotodetectorsSemiconductor DetectorsSemiconductor Device MaterialsSemiconductor PhysicsWide Band Gap SemiconductorsFocal Plane ArraysFocal Plane DetectorsP-i-n PhotodetectorsPassivationPhotodiodesQuantum EfficiencyResponsivitySuperlattice Materials
The authors report the most recent progress in Type II InAs/GaSb superlattice materials and photovoltaic detectors developed for focal plane array applications with a cutoff wavelength of ~8 μm. No turn-on of tunneling current was observed even at a reverse bias of -3 V for a 3 μm thick p-i-n photodiodes. The thermally-limited zero bias detectivity under 300 K 2 π FOV was 2~3×10<sup>11</sup> cm•Hz<sup>1/2</sup>/W at liquid nitrogen temperature, with a current responsivity of 2~3 A/W and a mean quantum efficiency of ~50%. Initial passivation using SiO<sub>2</sub> has shown to decrease the dark current by ~30% at a reverse bias of -1 V. The same detector structure was used for focal plane arrays with silicon readout integrated circuit. Concept proof of imaging was demonstrated with a format of 256×256 at liquid nitrogen temperature.