Topics in semiconductor physics: Part I. Phonons in semiconducting alloys and alloy superlattices ; Part II. Deep energy levels of defects in mercury cadmium telluride and wurtzite semiconductors
Kobayashi, Akiko
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/25300
Description
Title
Topics in semiconductor physics: Part I. Phonons in semiconducting alloys and alloy superlattices ; Part II. Deep energy levels of defects in mercury cadmium telluride and wurtzite semiconductors
Author(s)
Kobayashi, Akiko
Issue Date
1985
Doctoral Committee Chair(s)
Dow, J.D.
Department of Study
Physics
Discipline
Physics
Degree Name
Ph.D.
Degree Level
Dissertation
Date of Ingest
2011-06-06T17:12:36Z
Keyword(s)
semiconductors
phonons in semiconducting alloys
alloy superlattices
deep energy levels
mercury cadmium telluride
Wurtzite semiconductors
vibrational properties
Language
en
Abstract
This thesis consists of two parts. The first part is devoted to the study of vibrational properties of semiconducting alloys and alloy superlattices. The second part deals with deep energy levels of defects in semiconductors.
In Part I, densities of phonon states are evaluated using the recursion method for quasi-binary III-V semiconducting alloys: [equations]
metastable (III-V)1_xIV2x alloys: (GaSb)1_xGe2x and (GaAs)1_xGe2x; and alloy superlattices: GaAs/AtxGa1_xAs. New features in the densities of states, not present in those of the parent compounds, are associated with vibrations arising from various atomic arrangements in these substitutionally disordered alloys. For the alloy superlattices, the expected zone-folding effects are properly accounted for in the density-of-states spectra. Raman scattering data and infrared reflection data are interpreted based on the calculated densities of states for the above three systems. In spite of the neglect of long-range forces, the present calculations prove to be useful for a qualitative understanding of the observed mode behaviors and the
disorder-activated modes.
In Part II, deep energy levels of sp3-bonded impurities with the central-cell atomic-like defect potential are obtained using the Green's function technique. The host materials considered here are Hgl_xCdxTe alloys which have a narrow and variable band gap, and wurtzite semiconductors: AtN, CdS, CdSe, ZnS, and ZnO, which have large band gaps. A variety of defects responsible for trapping centers are identified. Our results would be instrumental in improving the quality of these technologically important materials.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
