Photoluminescence studies of Eu2+-Yb3+ co-doped BaMgAl10O17 phosphor synthesized by the combustion method

BaMgAl₁₀O₁₇:Eu²⁺,Yb³⁺ was investigated as a possible quantum cutting system to enhance solar cells efficiency. Phosphors were synthesized by combustion method and composed of nanorods. Photoluminescence spectra showed that Eu in the sample was reduced to bivalence while Yb remained trivalence. Through a cooperative energy transfer process, the obtained powders exhibited both blue emission of Eu²⁺ (around 450 nm) and near infrared emission of Yb³⁺ (around 1020 nm) under broad band excitation (250–410 nm) originating from 4f→5d transition of Eu²⁺. Energy transfer phenomenon between the sensitizer Eu²⁺ and the activator Yb³⁺ was investigated via the luminescent spectra and the decay curves of Eu²⁺ with different Yb³⁺ concentrations. Results indicated that energy transfer efficiency from Eu²⁺ to Yb³⁺ was not high. The poor efficiency can be explained by the long distance between rare earth ions.