Sub-millimeter-scale multijunction solar cells for concentrator photovoltaics (CPV)

International audienceConcentrator photovoltaic (CPV) technologies provide the highest photovoltaic conversion efficiency but remain too expensive for very large scale development. Reduction of the dimension (micro-CPV) is a promising approach towards cost reduction but necessitates sub-millimeter-scale high efficiency solar cells. In this paper, we review the challenges faced by sub-millimeter-scale solar cells for application in micro-CPV. We show that plasma etching processes are necessary to fabricate sub-millimeter-scale high-efficiency solar cells to avoid a waste of material in the isolation and dicing lines. We also show that despite the cell performance is known to degrade when the dimension of the cell is downscaled, this degradation can be negligible when optimized etching and passivation processes are used and when the cell operates under high concentration (