Growth and properties of hydrogenated amorphous silicon carbon alloys by DC reactive magnetron sputtering

We deposited amorphous hydrogenated silicon-carbon (a-Si$\rm\sb{1-x}C\sb{x}$:H) alloy films by dc reactive magnetron sputtering (RMS) of a silicon target in a plasma of (Ar + H$\rm\sb2$ + CH$\sb4).$ Films with optical bandgaps of 1.8-2.0 eV and x $\le$ 0.2 have a compact microstructure; no CH$\rm\sb{x}$ groups are detected by their stretching mode infrared absorption, and small angle X-ray scattering indicates a microvoid volume of $\le$2.5% for x $\le$ 0.3. The electronic properties are also excellent in terms of density of sub-bandgap defect states DOS, Urbach energy E$\rm\sb{U},$ ambipolar diffusion length L$\rm\sb{h},$ photoconductive mobility-lifetime product μ\tau and dark conductivity \rmσ\sb{D} for Tauc bandgap E$\rm\sb{g}\approx$ 1.90 eV. We attribute the quality of these films to the translational energy of the RMS growth flux, which leads to a dense and relatively homogeneous structure.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Yang, Siyuan

Contributors dc:contributor

• Abelson, John R.

• Engineering, Materials Science

Statement dc:rights

• Copyright 1995 Yang, Siyuan

Language dc:language

eng

Identifier

AAI9522190
(UMI)AAI9522190

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/22750