Abstract
We report the growth and characterization of type-II InAs/GaSb superlattice photodiodes grown on a GaAs substrate. Through a low nucleation temperature and a reduced growth rate, a smooth GaSb surface was obtained on the GaAs substrate with clear atomic steps and low roughness morphology. On the top of the GaSb buffer, a p+ -i- n+ type-II InAs/GaSb superlattice photodiode was grown with a designed cutoff wavelength of 4 μm. The detector exhibited a differential resistance at zero bias (R0 A) in excess of 1600 cm2 and a quantum efficiency of 36.4% at 77 K, providing a specific detectivity of 6× 1011 cm Hz /W and a background limited operating temperature of 100 K with a 300 K background. Uncooled detectors showed similar performance to those grown on GaSb substrates with a carrier lifetime of 110 ns and a detectivity of 6× 108 cm Hz /W.
Original language | English (US) |
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Article number | 223506 |
Journal | Applied Physics Letters |
Volume | 94 |
Issue number | 22 |
DOIs | |
State | Published - 2009 |
Funding
The authors would like to acknowledge Siamak A. Pour and Paritosh Manukar for their fruitful discussions and would like to thank Dr. Monte Turner and Ms. Barbara McQuinston from the Defense Advanced Research Projects Agency (DARPA) for their support and collaboration.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)