Micro-concentrated photovoltaics based on Cu(In,Ga)Se2 microcells: an optical studyNing Li, Chao Wang, Ye Tu, Jinming Zhang and Guanchao YinEur. Phys. J. Appl. Phys., 97 (2022) 1DOI: https://doi.org/10.1051/epjap/2021210215