Superlattices for Infrared Detectors.
Abstract
GaInSb/InAs superlattices have been grown and analyzed for use as high performance, high operating temperature 8 to 12 micron infrared detectors. Optical and transport properties favorable for long wavelength IR detection have been measured, and preliminary photoconductive and photovoltaic device structures have been fabricated and tested. Our results underscore the considerable potential of GaInSb/InAs superlattices to achieve detectivities comparable to HgCdTe at considerably higher operating temperatures. Such an improvement would be of significant benefit, both in reduced cost and complexity, to high performance DoD IR sensing systems. Molecular beam epitaxial (MBE) growth techniques were developed, yielding superlattices of exceptionally high structural quality, with uncompensated background doping in the low-to-mid 1015 cm-3 range, n-type. Methods for silicon doping the superlattices were established, allowing n-on-p and p-on-n photojunctions to be grown. Superlattice energy gaps were shown to span the infrared, and a 10-um absorption coefficient comparable to that of HgCdTe was measured, in agreement with theory. Initial unpassivated photovoltaic test devices show ROA = 0. 1 Omega-cm2 at 77K, for a 12-um cutoff. infrared, detector, stained layer, superlattice.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 30, 1992
- Accession Number
- ADA257511
Entities
People
- R. H. Miles
Organizations
- HRL Laboratories