Spectral Properties and Energy Transfer of a Potential Solar Energy Converter

The energy transfer between Ce 3+ and Eu 2+ has been investigated in the host Ca 3 Sc 2 Si 3 O 12 (CSS), prepared by a modified sol–gel method. Excitation and emission measurements from the near-infrared to the vacuum ultraviolet spectral regions have been performed upon CSS, Ce 3+ -doped CSS, Eu 2+ -doped CSS and Ce 3+, Eu 2+ -co-doped CSS, at various concentrations, including experiments at temperatures range of 15–460 K. The energy transfer efficiency from Ce 3+ to Eu 2+ can approach 90%, and the Ce 3+ donor decay curves for different Eu 2+ acceptor concentrations in the codoped system were fitted by the Inokuti–Hirayama method, indicating that it is energy transfer induced by electric dipole interaction. The use of the Ce 3+, Eu 2+ couple in the CSS host as a wideband harvester with an emission profile tailored to the response of the silicon solar cell in solar energy conversion suffers from two main drawbacks relating to valence instability and emission quenching of Eu 2+ . Possible solutions are suggested.