Objective:

1
MURI - Integrated NanosensorsIvan K. Schuller
UCSDCharacterization of InAs/GaSb Superlattices
for IR Imaging

• Objective
• Develop efficient InAs/GaSb IR detectors
• InAs/GaSb superlattice employed in IR focal plane
  array detectors. Efficiency of the detector may
  be limited by coherence length.
• Tune lattice spacing and coherence length using
  transition layers.
• Develop quantitative method to characterize
  InAs/GaSb superlattices with transition layers to
  optimize MBE growth.

UCSD SUPREX Refinement of AFRL InAs/GaSb
Superlattices
Strain Tuning Using Transition Layer

• Potential Benefits to Air Force
• More efficient InAs/GaSb focal plane arrays
• Faster development of materials for IR detectors
• Quantitative characterization of AFRL grown
  materials

• Results
• Suprex refinement method developed at UCSD used
  to analyze superlattices grown at AFRL.
• Suprex refinement determines strain profiles of
  InAs/GaSb superlattices containing InSb
  transition layers.
• 3. Minimum strain is obtained for 0.5 monolayer
  InSb transition layer.