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Proceedings Paper

Interconsistent band structure of narrow-gap Hg1-xCdxTe alloys obtained with consideration of far-band influence
Author(s): V. V. Bogoboyashchiy
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Paper Abstract

Faraday rotation, absorption spectra, and the intrinsic carrier concentration temperature dependencies were investigated in order to determine the interconsistent system of values of the narrow-gap Hg1-xCdxTe band parameters. The undoped and doped with indium or copper crystals with x < 0.315 were studied. The analysis of data of measuring was made with account of the far band influence. The value of matrix element P equals (8.1 +/- 0.08_ X 10-8 eV cm have been obtained with a high degree of certainty. The parameters of the second approach of the Kane model were found too: (gamma) 1 equals 4.0; (gamma) equals 0.7; (gamma) s equals 0.5. A new method of determination of the heavy hole effective mass have been elaborated and have been used successively in the heavy hole energy range (epsilon) < 0.15 eV. A new form of the light carrier dispersion relation and more exact relation for the temperature dependence of (epsilon) g have been obtained too. The heavy hole Hall factor at T equals 77 K, the heavy hole mobility at T equals 295 K, and the constant of valence band deformation potential E1 equals 12.5 eV have been determined. It has been found that doping of the material with indium, causes the appearance of donor states in the conduction band about 0.1 eV above the bottom of the band. The band structure of Hg1-xCdxTe (MCT) is studied for a long time, and its peculiarities are well known. The light carriers spectrum is believed to be described in framework of the 3-band Kane's model, and the parabolic approximation for heavy hole subband is thought to be sufficient as a rule. The influence of far bands is taken into account rather seldom. But at the same time, the values of band parameters obtained by different authors are not in a good agreement often. In result, it was impossible to agree with an acceptable accuracy the measured and the calculated values of some physical characteristics of MCT by using the known values of band parameters. In order to achieve perfect conformity between the theory and the experiment, another approach must be used. It is necessary that the complex experiment be carried out with a high accuracy of not only the measuring, but of the mathematical models of studied effects and the calculations too. All the main sources of systematic error should be revealed and removed, and the values of band parameters should be determined over again. Such a study was carried out, and its results are reported in this paper.

Paper Details

Date Published: 26 August 1997
PDF: 11 pages
Proc. SPIE 3182, Material Science and Material Properties for Infrared Optoelectronics, (26 August 1997); doi: 10.1117/12.280454
Show Author Affiliations
V. V. Bogoboyashchiy, Chysti Metaly (Ukraine)


Published in SPIE Proceedings Vol. 3182:
Material Science and Material Properties for Infrared Optoelectronics
Fiodor F. Sizov; Vladimir V. Tetyorkin, Editor(s)

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