Differentiation of photon generation in single- and bi- ligand europium complexes doped poly methyl methacrylate

Abstract Eu(DBM)3 and Eu(DBM)3Phen were introduced into poly methyl methacrylate (PMMA) in comparative, and the differential luminescence behaviors were revealed under ultraviolet (UV) radiation. The comparison of excitation behavior between Eu(DBM)3 and Eu(DBM)3Phen doped PMMAs indicates that the introduction of Phen ligand largely enhances the excitation intensity of europium in the entire UV region. The total quantum yield of Eu(DBM)3Phen doped PMMA was derived to be (9.34 ± 0.14)%, and it is about 8 times higher than that of the Eu(DBM)3 doped PMMA under 373 nm UVA light emitting diode (UVA-LED) excitation, which confirms the effective utilization of UVA radiation by introducing Phen ligand. Similar results on absolute spectral parameters of the bi-ligand under the excitation of 308 nm UVB light emitting diode (UVB-LED) further support the availability for photon conversion. The brilliant red fluorescence of Eu(DBM)3Phen doped PMMA under direct sunlight demonstrates the contribution of Phen to modify the solar spectrum and enhance the UV radiation conversion efficiency, which make the Eu(DBM)3Phen doped PMMA an attractive UV radiation conversion layer for solar cell.