Study of a micro-concentrated photovoltaic system based on Cu(In,Ga)Se₂ microcells array

We study a micro-concentrated photovoltaic (CPV) system based on micro solar cells made from a thin film technology, Cu(In,Ga)Se₂. We designed, using the ray-tracing software Zemax OpticStudio 14, an optical system adapted and integrated to the microcells, with only spherical lenses. The designed architecture has a magnification factor of 100x for an optical efficiency of 85% and an acceptance angle of ±3.5°, without anti-reflective coating. An experimental study is realized to fabricate the first generation prototype on a 5 cm x 5 cm substrate. A mini-module achieved a concentration ratio of 72x under AM1.5G, and an absolute efficiency gain of 1.8% for a final aperture area efficiency of 12.6%.