Study of Noise and Defect Levels in Infrared Cadmium Mercury Telluride

摘要

The objective this HBCU program was to measure the different types of signal noise in mercury cadmium telluride (MCT) materials, and to correlate the type and magnitude of the noise to measured defect levels in the same samples. This type of study had been previously been done for thick MCT layers grown by liquid phase epitaxy decades ago. This program was to look at the more advanced epitaxial MCT layers grown by molecular beam epitaxy. Samples were measured with a Noise Spectrum Analyzer down to cryogenic temperatures and by a Photo-Induced Current Spectroscopy Technique. Results of these measurements showed that the 1/ f noise in the MCT epitaxial samples was indicative of interface states between the epilayer and the substrate, and not due to alloy fluctuations in the epilayer.