Time-resolved Raman scattering in GaAs multiple quantum well structures
Oberli, Daniel Yves
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/2142/23899
Description
Title
Time-resolved Raman scattering in GaAs multiple quantum well structures
Author(s)
Oberli, Daniel Yves
Issue Date
1988
Doctoral Committee Chair(s)
Klein, Miles V.
Department of Study
Physics
Discipline
Physics
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
time-resolved Raman scattering
GaAs
multiple quantum well structures
intersubband relaxation
Language
en
Abstract
This thesis describes an optical study of the intersubband relaxation of carriers in GaAs multiple quantum well structures. For this investigation the application of the conventional Raman scattering technique was extended to the picosecond time domain. Inelastic light scattering from the elementary intersubband excitations of an electron-hole plasma reveals both the absolute carrier density and the occupancy of the electronic subbands of a GaAs quantum welL The major result of this investigation concerns the role of the intersubband scattering processes in the relaxation of carriers following their excitation in a GaAs quantum well by a short optical pulse. Carriers generated on the second subband of a wide quantum well relax towards the bottom of the well by the emission of acoustic phonon. Their lifetime is found equal to 325±25 picoseconds in a 215 A multiple quantum well structure, whereas in a narrower well (116 A) the lifetime is reduced behond our experimental time resolution of 8 ps, presumably caused by the faster relaxation mechanism corresponding to the emission of an optical phonon. A theoretical calculation of the scattering rate by longitudinal acoustic phonon supports the existence of a long-lived electron population on the second subband of a wide GaAs quantum well.
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.
