“…For example, Yamaguchi et al predicted more than 45% efficiency in fields concentrator solar cells intensively studied for the application of CPV (Concentrator photovoltaic) [2], but the highest efficiency everachieved is 44.2% in 2013 by Sharp Corporation [5][6]. Most recently, a series of researches that was based on the practical limit of the material improvement to various materials like Si, III-V, II-VI thin films, organic, and Perovskite, as well as various configurations like quantum dots, hetero-junction, and multi-junction, has been published [7][8][9][10][11]. Obviously, these kinds of efficiency-limit studies tend radiation coupling would be adequate to suppress the spectrum mismatching loss [57][58][59][60].…”