Microscale solar cells for high concentration on polycrystalline Cu(In,Ga)Se 2 thin films

We report high concentration experiments on polycrystalline thin film solar cells. High level regime is reached, thanks to the micrometric scale of the Cu(In,Ga)Se 2 cells, which strongly decreases resistive losses. A 4% absolute efficiency increase is obtained at a concentration of ×120, and current densities as high as 100 A/cm 2 can be measured. These results show that the use of polycrystalline thin films under high concentration is possible, with important technological consequences.