The use of convex lens as primary concentrator for multi-junction solar cellsJuan Paolo Lorenzo Gerardo Barrios, John Raffy Cortez, Gene Michael Herman, Aris Larroder, Bernice Mae Yu Jeco, Kentaroh Watanabe and Yoshitaka OkadaEmergent Scientist, 2 (2018) 5DOI: https://doi.org/10.1051/emsci/2018004