Preparation and evaluation of the rare earth doped nanoparticle SiO 2–PVP hybrid thin film by sol–gel method

Abstract

For the purpose of development of high-luminosity and high-scattering photoluminescence materials, we studied preparation and evaluation of the thin films of firstly SiO 2 nanoparticles with the particle size of 10–30 nm and next, SiO 2–PVP inorganic–organic hybrid ones with the sizes 100–150 nm, both doped with the rare earth (RE) Eu ions by the sol–gel method. Application of the former nanoparticles is expected to increase light scattering effect. For the hybrid film, the starting sol was C 2H 5OH solutions of silicon-alkoxide Si(OC 2H 5) 4 doped with Eu(fod) 3 complexes and polymer resin PVP, in which NH 4OH was used for promoting hydroxis. The FE-SEM observation for the obtained film surface revealed formations of homogeneously high-density nanoparticle SiO 2 spheres with the sizes 100–150 nm. The SiO 2–PVP hybrid thin film exhibited higher PL and PLE by 50% than only PVP thin film. The PL spectra showed mainly sharp lines with the peaks of 580, 592 and 614 nm, and were assigned to the f–f transitions of Eu 3+(4f 6) through thermal transfer from the excited singlet and triplet states for Eu(fod) 3 complexes.