Photoluminescent hybrid thin films fabricated with lanthanide ions covalently bonded silica

Abstract

Silica-based organic–inorganic hybrid thin solid films were fabricated via a spin coating sol–gel process technology. Among tetraethoxysilane (TEOS) and a kind of modified monomer (abbreviated as PZC-APTES) derived from grafted 2-pyrazinecarboxylic acid (PZC) with (3-aminopropyl)triethoxysilane (APTES) were used as the inorganic and organic components. Through the hydrolysis and polycondensation process of both TEOS and PZC-APTES, lanthanide ions were introduced in the hybrid systems through the coordination to the monomer. Controlling the sol–gel process by spin coating over the quartz substrate for 2 days, the hybrid thin films were achieved. The final solid films exhibited strong red luminescence (Eu 3+) and green luminescence (Tb 3+), suggesting that the intramolecular energy transfer process occurs for the suitable energy match between the triplet state energy of organic ligand and the emissive energy level of lanthanides.