Broadband Near-Infrared Quantum Cutting in Eu[sup 2+] and Yb[sup 3+] Ions Co-doped CaAl[sub 2]O[sub 4] Phosphor

A and coactivated phosphor that can cut one photon in UV and visible regions into two near-infrared (NIR) region photons could be used as a downconversion luminescent convertor in front of crystalline silicon solar cells to reduce the thermalization loss. The luminescence spectra in both visible and NIR regions and the luminescence decay curves of were recorded to provide a direct evidence of energy transfer from to ions. The highest energy transfer efficiency was estimated to be 55.05%. The results indicate that is a potential ion couple which may be used to improve the solar cell efficiency.