Thin Film Solar Cells
Fabrication, Characterization and Applications
Chapter One
Epitaxial Thin Film Crystalline
Silicon Solar Cells on low Cost
Silicon Carriers
Jef Poortmans
IMEC, Leuven, Belgium
1.1 INTRODUCTION
In order to substantially reduce the costs of present crystalline Si solar cells, the material
consumption of highly pure Si in a typical solar cell structure should be reduced. Most of
the crystalline Si material merely acts as a mechanical carrier for the solar cell device with
most of the optical absorption taking place in the upper 30 µm region. When special care
is taken to maximize optical confinement active layer thicknesses as low as 0.5 µm would
be sufficient for reaching energy conversion efficiencies above 15 %. Moving to thinner
Si wafers to reduce Si consumption represents one option, but there are obvious concerns
about process yield, showing up when producing cells in Si-wafers with thicknesses below
200 µm. Special substrate types, specifically developed to avoid crack propagation, like the
tri-crys ... read full excerpt from Thin Film Solar Cells: Fabrication, Characterization and Applications ebook
