Fundamental Study of Defects and Their Reduction in Type-II Superlattice Materials
Abstract
The project was motivated by the advantages offered by antimony-based type-II superlattice (T2SLs) for MWIR (Midwave Infrared) and LWIR (Long-Wave Infrared) laser and detector applications due to their broad bandgap tunability and material uniformity. The performance of T2SL IR detectors is predicted to be superior to that of MCT (HgCdTe) IR detectors. Previous research on novel T2SL structures has demonstrated significant progress and interesting device physics, but the predicted high performance has yet to be realized as T2SL IR detectors are still limited by defects and interface-related traps. A thorough understanding of defect physics, growth processes, and detector theory is thus crucial for the suppression of defect formation and their adverse effects. To achieve this, the project brought together a team of experts in MBE and MOCVD growth, device theory, device fabrication and characterization, Raman spectroscopy, X-ray diffraction, transmission electron microscopy.The main objectives of the project are to: 1) Identify and understand the origin of point defects, line defects, interfacial traps, and surface states in T2SL structures through experimental studies closely coupled to theoretical modeling. 2) Correlate defect properties with device performance as a function of operating temperature, including minority carrier lifetime, detector noise, dark current, breakdown voltage, shunt resistance, and surface recombination. 3) Examine novel MBE and MOCVD growth methods and passivation techniques that eliminate and or mitigate defects in InAs/GaSb, InAs/InGaSb, and InAs/InAsSb T2SLs. 4) Develop a comprehensive device physics model that includes extrinsic material properties to accurately predict device performance and provide vital device design rules. During the course of project, to address the research challenges faced by the team, team members also undertook efforts to develop new characterization techniques and methodologies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 04, 2018
- Accession Number
- AD1059423
Entities
People
- David J Smith
- Jian-Min Zuo
- Kuang-chien Hsieh
- Russell D. Dupuis
- Yong Zhang
- Yong-hang Zhang
Organizations
- University of Illinois Urbana–Champaign