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1 June 2011 XBn barrier photodetectors based on InAsSb with high operating temperatures
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We demonstrate the suppression of the bulk generation-recombination current in nBn devices based on an InAsSb active layer (AL) and a AlSbAs barrier layer (BL). This leads to much lower dark currents than in conventional InAsSb photodiodes operating at the same temperature. When the BL is p-type, very high doping must be used in the AL (nBpn+). This results in a significant shortening of the device cutoff wavelength due to the Moss-Burstein effect. For an n-type BL, low AL doping can be used (nBnn), yielding a cutoff wavelength of ∼4.1 μm and a dark current close to ∼3 × 10−7 A/cm2 at 150 K. Such a device with a 4-μm-thick AL will exhibit a quantum efficiency (QE) of 70% and background-limited performance operation up to 160 K at f/3. We have made nBnn focal plane array detectors (FPAs) with a 320 × 256 format and a 1.3-μm-thick AL. These FPAs have a 35% QE and a noise equivalent temperature difference of 16 mK at 150 K and f/3. The high performance of our nBnn detectors is closely related to the high quality of the molecular beam epitaxy grown InAsSb AL material. On the basis of the temperature dependence of the diffusion limited dark current, we estimate a minority carrier lifetime of ∼670 ns.
©(2011) Society of Photo-Optical Instrumentation Engineers (SPIE)
Philip Klipstein, Olga Klin, Steve Grossman, Noam Snapi, Inna Lukomsky, Daniel Aronov, Michael Yassen, Alexander Glozman, Tal Fishman, Eyal Berkowicz, Osnat Magen, Itay Shtrichman, and Eliezer Weiss "XBn barrier photodetectors based on InAsSb with high operating temperatures," Optical Engineering 50(6), 061002 (1 June 2011).
Published: 1 June 2011


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