Abstract
We report the most recent result in the area of type-II InAs/GaSb superlattice photodiodes that have a cutoff wavelength around 7 μm at 77 K. Superlattice with a period of 40 Å lattice matched to GaSb was realized using GaxIn1-x type interface engineering technique. Compared with significantly longer period superlattices, we have reduced the dark current density under reverse bias dramatically. For a 3 μm thick structure, using sulfide-based passivation, the dark current density reached 2.6×10-5 Acm2 at -3 V reverse bias at 77 K. At this temperature the photodiodes have R0A of 9300 Ω cm2 and a thermally limited zero bias detectivity of 1×1012 cm Hz12W. The 90%-10% cutoff energy width was only 16.5 meV. The devices did not show significant dark current change at 77 K after three months storage in the atmosphere.
| Original language | English (US) |
|---|---|
| Article number | 091109 |
| Pages (from-to) | 1-3 |
| Number of pages | 3 |
| Journal | Applied Physics Letters |
| Volume | 86 |
| Issue number | 9 |
| DOIs | |
| State | Published - Feb 28 2005 |
Funding
This work was partially funded under Air Force Contract No. F49620-01-1-0087. The authors are grateful for support from Dr. G. Brown, Dr. P. LeVan, Dr. A. Hahn from the Air Force Research Laboratory (AFRL). One of the authors (Y.W.) is supported under the Cabell Fellowship at Northwestern University.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)