“Third generation” photovoltaics and silicon nanostructures

Summary form only given. The photovoltaics market is currently booming with most of the product sold being ldquofirst generationrdquo solar cells relying on the use of expensive silicon wafers. Potentially much lower cost ldquosecond generationrdquo thin-film technology, where the photoactive material is deposited directly onto a supporting substrate is now starting to appear on the market. The future of this promising renewable energy technology depends on streamlining the costs of such thin-film approaches while improving the energy conversion efficiency. Particularly important may be ldquothird generationrdquo approaches which are thin-film approaches incorporating advanced schemes for improving the solar energy conversion efficiency beyond that possible with traditional approaches. A cross-section of these advanced concepts and progress in their experimental realisation will be described with particular emphasis on the work in the speakerpsilas group on ldquoall-siliconrdquo tandem cells and ldquohot carrierrdquo cells.