| Person in charge of the project: |
Silicon nanowires for all-Silicon based tandem solar cells.|
Dual- or multi-junction solar cells, being the only proven concept to increase the efficiency above the single-junction solar cell efficiency limit, require materials with the right combination of bandgaps to minimize thermalization losses. The most straightforward way to engineer bandgaps so far has relied on III-V materials. These materials have resulted in very efficient but also very expensive solar cells. If a higher bandgap Si material suitable for solar cells could be developed, a fully Si-based dual-junction cell could be envisaged at a much lower cost. A very interesting way to obtain a high bandgap Si material is through quantum confinement in Si nanowires. Since the discovery of efficient photoluminescence in porous Si, it has been shown that in Si nanowires it is possible to increase the bandgap and to change its nature from indirect to direct. The advantage of the nanowires is also that they are 1D structures with good conduction in their longitudinal direction. All these aspects make nanowires an interesting material to investigate for application in a top cell of an entirely Si-based dual-junction solar cell.
Faculty of Engineering
Doctoral Programme in Engineering
Duration of the project:
01.01.2009 - 31.12.2012