Research Projects

MURI-ARO: Fundamental Research on Infrared Detection

Research Collaborators:
Professors S. L. Chuang (PI), K. Y. Cheng, Milton Feng, K. C. Hsieh, Paul D. Coleman, Nick Holonyak Jr., Y.-C. Chang (Dept. of Physics) and Jeff White (Material Research Laboratory) at the University of Illinois, Professor Russell Dupuis at the University of Texas – Austin, and Professor Wen Wang at Columbia University.

Transition Partners: 
DRS IR Technologies, HRL Labs, Applied Optoelectronics, ARL, Army Center for Night Vision & Electro-Optics, JPL and Sandia National Laboratory.

Duration:
May 2001 to May 2006

This project has three main objectives:

1. Investigation of defects in HgCdTe photodetectors
2. Design and fabrication of novel antimony-based type-II quantum-cascade photodetectors.
3. Fabrication of strain-balanced quantum-dot infrared photodetectors (QDIP) using III-V material systems.

Approaches:

1. Identify structure and point defects (TEM, XPS) and optical characterization of defects (PL, FTIR) in HgCdTe systems.
2. InAs/InGaSb type-II superlattice photodetector design and fabrication by MBE.
3. Strain-balanced multiple QDIP structure:
   • Eliminate defects through strain-balanced QDIP structures using tensile strained InGaP barrier.
   • InAsSb QDIP using strain compensation: InAsSb QD on GaSb with InAsSb barriers.

Within the study of quantum dot infrared photodetectors (QDIPs), research is being carried out to:

1. Investigate the growth process and its effects on QD size and density
2. Study the effects of barrier thickness and material on QD properties (barrier material: GaAs, InGaP)
3. Ultimately use these results to grow a high-performance QDIP

AFM image (1x1 mm) of InAs QDs on GaAs