NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Due to the lapse in federal government funding, NASA is not updating this website. We sincerely regret this inconvenience.

Back to Results
Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenideThe project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.
Document ID
19950020360
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Patterson, James D.
(Florida Inst. of Tech. Melbourne, FL, United States)
Li, Wei-Gang
(Florida Inst. of Tech. Melbourne, FL, United States)
Date Acquired
September 6, 2013
Publication Date
March 19, 1995
Subject Category
Solid-State Physics
Report/Patent Number
NAS 1.26:197835
NASA-CR-197835
Report Number: NAS 1.26:197835
Report Number: NASA-CR-197835
Accession Number
95N26780
Funding Number(s)
CONTRACT_GRANT: NAG8-1094
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available