Up-conversion luminescence of erbium (III) oxalate nanoparticles/titania/y-Glycidoxypropyltrimethoxysilane composite sol-gel thin films

Erbium (III) oxalate nanoparticles dispersed titania/y-Glycidoxypropyltrimethoxysilane composite materials for photonic applications were prepared by a chemical approach combining the microemulsion technique and the sol-gel method at low temperature. Transmission electron microscopy observation shows that the size of the erbium (III) oxalate nanoparticles is in the range from 10 to 40 nm. A relatively strong room-temperature green up-conversion emission at 543 nm (⁴S_3/2→⁴I_15/2) has been measured for the composite thin films with different erbium oxalate content and heat treatment temperature upon excitation at 993 nm. The lifetime of the visible up-conversion emission has been measured. UV-visible transmission spectroscopy results showed that a relatively high transparency (in the visible range) composite thin film could be obtained at a suitably low heat treatment temperature.