Spectral Properties and Energy Transfer of a Potential Solar Energy Converter

The energy transfer between Ce3+ and Eu2+ has been investigated in the host Ca3Sc2Si3O12 (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, Ce3+-doped CSS, Eu2+-doped CSS and Ce3+, Eu2+-co-doped CSS, at various concentrations, including experiments at temperatures range of 15–460 K. The energy transfer efficiency from Ce3+ to Eu2+ can approach 90%, and the Ce3+ donor decay curves for different Eu2+ 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 Ce3+, Eu2+ 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 Eu2+. Possible solutions are suggested.