Electrical Conduction of Surfaces of III-V Materials and Superlattices: Mechanisms and Their Control
Abstract
Type 2 superlattices (T2SLs) constructed of III-V materials are being widely investigated for infrared detectors in the MWIR and LWIR spectral regions, because of their reduced Auger generation and ability to reach to longer wavelengths. The device architecture of choice uses a unipolar barrier design, rather than the older pn-junction-based designs, because of unipolar barriersÕ superior ability to block many types of dark current. An ongoing difficulty in the development of T2SL unipolar barrier detectors is surface leakage current. Although bulk current mechanisms have been completely understood for many decades, there remains only incomplete understanding of the mechanisms of surface currents. This program will address these issues, investigating the fundamental mechanisms of surface currents and devising approaches to suppress surface leakage in T2SL detectors. Surface electrical conductivity types of III-V materials and superlattices will be measured and modeled, and surface band diagrams of unipolar barrier structures will be developed. Temperature and voltage dependence of surface currents of T2SLÕs will be experimentally measured, and the resulting surface leakage current mechanisms will be determined. With the acquired understanding of surface leakage current mechanisms, new approaches will be developed to suppress surface leakage in T2SL infrared detectors. The immediate benefit of the proposed research is improved T2SL infrared detector performance through suppressed surface leakage. More broadly, a fundamental understanding of the mechanisms of surface currents in semiconductors may benefit a wide range of semiconductor devices.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810403
Entities
People
- Gary Wicks
Organizations
- Army Contracting Command
- United States Army
- University of Rochester