Luminescence Properties of Thermally Stable Silica Incorporated Dysprosium β-Diketonate Complexes

Abstract

In the present work, silica incorporated complexes of Li[Dy(acac)4], Na[Dy(acac)4], K[Dy(acac)4] were prepared. The Field Emission Scanning Electron Microscopy, diffuse reflectance, photoluminescence and thermal properties of synthesized complexes were studied. The Fourier Transform Infrared spectra confirm the incorporation of silica in complexes. Silica incorporation enhances the thermal stability of the materials. UV-VIS spectra show absorption band from 200 to 350 nm for electronic transition of the ligand. Similar absorption band was observed in the excitation spectra. Emission spectra show two prominent peaks at 485 nm and 575 nm in the blue and yellow regions respectively. Photometric characterization indicates the color coordinates of Na[Dy(acac)4]/SiO2 complex in the white light region upon the UV light excitation. The incorporation of silica enhances the intersystem crossing and decreases the excited state lifetime. Among the three complexes, sodium-based complex shows the color coordinate (0.35, 0.38) very close to near white light with CCT value comparable to the day light. The shorter excited state life time (18.91 μs) and photometric characterization suggest that these complexes can be used as light emitting layer.