Applied Physics Letters · 2011 · 110 citations · 10 references
EngineeringElectrical EngineeringMaterials ScienceOpticsOptoelectronicsPhotonicsDetector TechnologyInfrared DetectorsOptical DetectorsPhotodetectorsSemiconductor DetectorsWide-bandgap Semiconductor DevicesDark CurrentDetector Quantum EfficiencyFocal Plane ArraysFocal Plane DetectorsHeterojunction PhotodetectorsInfrared PhotodetectorsPhotodiode ArraysQuantum Efficiency
The dominant dark current mechanisms are identified and suppressed to improve the performance of midwave infrared InAs/GaSb type-II superlattice photodiodes at high temperatures. The optimized heterojunction photodiode exhibits a quantum efficiency of 50% for 2 μm thick active region without any bias dependence. At 150 K, R0A of 5100 Ω cm2 and specific detectivity of 1.05×1012 cm Hz0.5/W are demonstrated for a 50% cutoff wavelength of 4.2μm. Assuming 300 K background temperature and 2π field of view, the performance of the detector is background limited up to 180 K, which is improved by 25 °C compared to the homojunction photodiode. Infrared imaging using f/2.3 optics and an integration time of 10.02 ms demonstrates a noise equivalent temperature difference of 11 mK at operating temperatures below 120 K.
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A new semiconductor superlattice
G.A. Sai-Halasz, Raphael Tsu, L. Esaki · Applied Physics Letters · 1977 · 564 citations