View article

Near-infrared quantum cutting involving the emission of near-infrared photons by downconversion cooperative energy transfer from Eu 2+ to Yb 3+ in borate glasses was reported. Electron spin resonance spectra and absorption spectra were measured to prove the existence of Eu 2+ in borate glasses. Excitation, emission, and fluorescence decay measurements were performed to examine the occurrence of cooperative energy transfer from Eu 2+ to Yb 3+ ions. Yb 3+ concentration dependent quantum efficiency was calculated and the maximum efficiency approaches 164.19%.