Photovoltaic Devices

As part of a collaboration with the LN2 of the University of Sherbrooke, a new multi-junction solar cell architecture with through vias was proposed for concentrated photovoltaics (3% gain hoped for). The first technological obstacle to this new architecture was overcome by developing a plasma process allowing the structuring of vias 40 µm deep through the III-V/Ge heterostructure with minimal damage to the sides (Figure 6). By introducing hydrogen into plasma chemistry, electrical characterizations of the cell showed that non-radiative recombination losses at the sidewalls of III-V semiconductors are very limited, since the open circuit voltage (sensitive electrical parameter surface conditions) of the cell with vias is almost identical to that without vias (-0.1% reduction only).