LAUSR

In this study, we investigated the quantum cutting (QC) mechanism in Eu2+–Nd3-co-doped SrAl2O4 microcrystals by fluorescence spectroscopy and decay lifetime analysis. In this material, the near-infrared (NIR) emissions of Nd3+ in the range of 800–1200 nm were enhanced under the excitation of the Eu2+:4f7 → 4f65d1 transition radiation. The lifetime of the 5d1 level of Eu2+ decreased with the increase in the Nd3+ concentration. These results verified the occurrence of cooperative energy transfer (CET) from the Eu2+:5d1 excited state to the Nd3+:4F3/2 level, by which one absorbed ultraviolet-visible photon was converted to two NIR photons with an optimal quantum efficiency (QE) of approximately 177.1%. Therefore, this broadband QC material paves the way for a further increase in the conversion efficiency of c-Si solar cells.