Abstract
We demonstrate the suppression of the bulk generationrecombination 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 × 107 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 madenBnn 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.
Original language | English |
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Article number | 061002 |
Journal | Optical Engineering |
Volume | 50 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2011 |
Externally published | Yes |
Bibliographical note
Funding Information:The material in this paper is based on work supported by the Defense Advanced Research Projects Agency (DARPA) under Contract No. HR0011-08-C-0063. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the DARPA, the U.S. Department of Defense, or the U.S. Government. The authors acknowledge technical support from S. Greenberg, who was responsible for the smooth operation of the two MBE machines, and B. Yariv, H. Moshe, H Schanzer, Y. Caracenti, D. Gur, and S. Weinstein, who have all contributed to the successful processing, packaging, or characterization of the devices.
Funding
The material in this paper is based on work supported by the Defense Advanced Research Projects Agency (DARPA) under Contract No. HR0011-08-C-0063. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the DARPA, the U.S. Department of Defense, or the U.S. Government. The authors acknowledge technical support from S. Greenberg, who was responsible for the smooth operation of the two MBE machines, and B. Yariv, H. Moshe, H Schanzer, Y. Caracenti, D. Gur, and S. Weinstein, who have all contributed to the successful processing, packaging, or characterization of the devices.
Funders | Funder number |
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Defense Advanced Research Projects Agency |
Keywords
- Shockley-Read-Hall
- XBn
- diffusion currents
- generation-recombination
- high operating temperatures
- indium arsenide antimonide
- infrared detectors
- nBn