Electronic transport properties of thin films of amorphous silicon
type: CreativeWork
description: The work reported in this thesis was carried out at the Physics Department of Dundee College of Technology between May 1980 and October 1983. The aims of the work were; (i) to develop a computer-based system for the capture and analyses of fast transient waveforms, with particular emphasis on the "Time of Flight" experiment, (ii) to commission an r.f. sputter-deposition system capable of producing thin films of amorphous Silicon, and to evaluate the electronic transport properties of the material prepared over a wide range of deposition conditions, and (iii) to investigate the electronic transport properties of thin films of co-sputtered Silicon-Aluminium and Silicon-Antimony, and to evaluate the effectiveness of Aluminium and Antimony as electronic dopants. The apparatus constructed consists of an electron-gun capable of firing a pulsed electron beam, in the energy range 4-15 keV, at the top metallic contact of a semiconductor specimen. A Datalab DL905 transient recorder was used to capture and digitise the characteristic waveforms, these waveforms being sent to the College's Dec-System-20 mainframe computer for analyses, via a NASCOM microcomputer. Computer programs were developed for the control of the experimental equipment and for the capture and analyses of the transient waveforms. Dark d.c. conductivity, electron drift mobility, transient and steady state photoconductivity and optical absorption experiments were carried out on thin films of amorphous Silicon. These measurements reveal wide variations in the electronic transport properties of specimens of amorphous Silicon prepared under seemingly identical deposition conditions. The experimental results are interpreted in terms of localised conduction band tail states extending to approximately 0.2 eV below the conduction band mobility edge, and a discrete set of localised states situated at 0.4 eV below the conduction band mobility edge. It is suggested that the extent of the tail states and the density of t…
abstract: The work reported in this thesis was carried out at the Physics Department of Dundee College of Technology between May 1980 and October 1983. The aims of the work were; (i) to develop a computer-based system for the capture and analyses of fast transient waveforms, with particular emphasis on the "Time of Flight" experiment, (ii) to commission an r.f. sputter-deposition system capable of producing thin films of amorphous Silicon, and to evaluate the electronic transport properties of the material prepared over a wide range of deposition conditions, and (iii) to investigate the electronic transport properties of thin films of co-sputtered Silicon-Aluminium and Silicon-Antimony, and to evaluate the effectiveness of Aluminium and Antimony as electronic dopants. The apparatus constructed consists of an electron-gun capable of firing a pulsed electron beam, in the energy range 4-15 keV, at the top metallic contact of a semiconductor specimen. A Datalab DL905 transient recorder was used to capture and digitise the characteristic waveforms, these waveforms being sent to the College's Dec-System-20 mainframe computer for analyses, via a NASCOM microcomputer. Computer programs were developed for the control of the experimental equipment and for the capture and analyses of the transient waveforms. Dark d.c. conductivity, electron drift mobility, transient and steady state photoconductivity and optical absorption experiments were carried out on thin films of amorphous Silicon. These measurements reveal wide variations in the electronic transport properties of specimens of amorphous Silicon prepared under seemingly identical deposition conditions. The experimental results are interpreted in terms of localised conduction band tail states extending to approximately 0.2 eV below the conduction band mobility edge, and a discrete set of localised states situated at 0.4 eV below the conduction band mobility edge. It is suggested that the extent of the tail states and the density of t…
author: Fortuna, Henry
language: eng
date published: 1984-11
date modified: 2026-07-24T00:50:23Z
provider: Abertay University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Abertay University