Synthesis and optical properties of a new fluorinated erbium complex/polymer composite material

摘要

A new fluorinated erbium complex with pentafluorobenzoate groups and triphenylphosphine oxide ligands, Er(PFBZ)_3(TPPO)_2 (PFBZ: pentafluorobenzoate, TPPO: triphenylphosphine oxide), was synthesized and characterized. And Er(PFBZ)_3(TPPO)_2/PMMA (polymethyl methacrylate) composite material was made by bulk polymerization. Both emission properties of the pure complex in the solid and that embedded in PMMA matrix were investigated upon excitation at different wavelengths. The luminescent intensity of the complex embedded in PMMA was enhanced strongly through the indirect excitation of the ligands absorption. Judd-Ofelt theory is used to analyze the absorption spectrum of Er~(3+) in PMMA matrix and obtain the intensity parameters: OMEGA_2 = 11.343 X 10~(-20) cm~2, OMEGA_4 = 1.474 X 10~(-20) cm~2 and OMEGA_6 = 1.001 X 10~ (-20) cm~2. Based on these parameters, the radiative lifetime of the excited ~4I_(13/2) level and the stimulated emission cross-section for the ~4I_(13/2) - > ~4I_(15/2) transition are also evaluated.