Optimization of thin film silicon solar cells on highly textured substrates

Doped layers made of nanostructured silicon phases embedded in a silicon oxide matrix were implemented in thin film silicon solar cells. Their combination with optimized deposition processes for the silicon intrinsic layers is shown to allow for an increased resilience of the cell design to the substrate texture, with high electrical properties conserved on rough substrates. The presented optimizations thus permit turning the efficient light trapping provided by highly textured front electrodes into increased cell efficiencies, as reported for single junction cells and for amorphous silicon (a-Si)/microcrystalline silicon tandem cells. Initial and stabilized efficiencies of 12.7 and 11.3%, respectively, are reported for such tandem configuration implementing a 1.1 mu m thick microcrystalline silicon bottom cell.