Skip to content Skip to navigation
University of Warwick
  • Study
  • |
  • Research
  • |
  • Business
  • |
  • Alumni
  • |
  • News
  • |
  • About

University of Warwick
Publications service & WRAP

Highlight your research

  • WRAP
    • Home
    • Search WRAP
    • Browse by Warwick Author
    • Browse WRAP by Year
    • Browse WRAP by Subject
    • Browse WRAP by Department
    • Browse WRAP by Funder
    • Browse Theses by Department
  • Publications Service
    • Home
    • Search Publications Service
    • Browse by Warwick Author
    • Browse Publications service by Year
    • Browse Publications service by Subject
    • Browse Publications service by Department
    • Browse Publications service by Funder
  • Help & Advice
University of Warwick

The Library

  • Login
  • Admin

A theoretical study of the properties of photoexcited hot carriers in germanium

Tools
- Tools
+ Tools

Noguera Becerra, Alejandro (1978) A theoretical study of the properties of photoexcited hot carriers in germanium. PhD thesis, University of Warwick.

[img]
Preview
PDF
WRAP_Theses_Noguera_Becerra_1978.pdf - Unspecified Version - Requires a PDF viewer.

Download (4Mb) | Preview
Official URL: http://webcat.warwick.ac.uk/record=b1750168~S15

Request Changes to record.

Abstract

This thesis is about a theoretical study of the properties of photoexcited holes in p-type Ge samples at low temperatures. The emphasis is on those carriers which are in non-equilibrium with the lattice. The energy distribution function for these carriers are obtained by a numerical solution of a rate equation which involves excitation, recombination and lattice scattering. Two models of a semiconductor are considered. The complicated band structure of p-type Ge is first approximated by a parabolic heavy hole band; later developments make necessary the inclusion of a parabolic light hole band.

Two types of photoexcitation are analysed. In the first, carriers are generated by a narrow spectrum of photoexcitation and the distribution function is studied as function of the initial excitation energy, the spectrum bandwidth and the density of the compensating impurities. For a very narrow excitation spectrum, the distribution of carriers exhibits a series of equally spaced peaks at carrier wavevectors equal to and below the photoexcitation wavevector. At compensation densities greater than or about equal to 10¹³ cm-³ and photoexcitation energies about 30 meV the distribution function resembles a Maxwellian function with carriers temperature much greater than that of the lattice.

The second excitation spectrum involves room temperature black- body radiation. In the one band model, the distribution function is, for Cu-doped Ge with compensation densities less than or equal to 10¹³ cm-³) nearly a Maxwellian function with the carrier temperature obtained from an energy balance equation. Good agreement with experimental mobility data is found for the same compensation densities. For higher compensation densities a parabolic light hole band is then included in the model of semiconductor and the experimental photohall mobility data for Cu-and Ga-doped Ge samples are used to deduce a value for the deformation potential a. This parameter is found to depend on both the compensation density and lattice temperature.

It is also reported additional calculations which suggest ways to improve the theoretical model.

Item Type: Thesis (PhD)
Subjects: Q Science > QC Physics
Q Science > QD Chemistry
Library of Congress Subject Headings (LCSH): Germanium, Hot carriers, Photons, Photoelectrochemistry, Photoabsorption
Official Date: March 1978
Dates:
DateEvent
March 1978Submitted
Institution: University of Warwick
Theses Department: Department of Physics
Thesis Type: PhD
Publication Status: Unpublished
Supervisor(s)/Advisor: Hearn, C. J.
Sponsors: Universidad de los Andes (Mérida, Venezuela)
Extent: iv, 129 leaves : illustrations, charts
Language: eng

Request changes or add full text files to a record

Repository staff actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics

twitter

Email us: wrap@warwick.ac.uk
Contact Details
About Us