Structural and luminescence properties of undoped and Eu-doped SiOC thin films

We report on the investigation of the structural, chemical and optical properties of undoped and Eu-doped SiOC thin films synthetized by RF magnetron sputtering. Undoped SiOC exhibits an intense room temperature luminescence at similar to 500 nm, and an important contribution to this signal is due to the presence of Si-C bonds. Moreover, when inserted in a SiOC matrix, Eu ions have a higher solid solubility with respect to pure SiO2; as a consequence, we observe a reduction of Eu clustering phenomena. Furthermore the reducing properties of SiOC, related to the presence of C, allow the prevalence of the Eu2+ emission over the Eu3+ one. Through the control of the annealing conditions it is possible to obtain an intense light emission at 440 nm. These properties propose SiOC as a novel and efficient Si-based host matrix for Eu and open the way to promising perspectives of Eu-based materials for photonic applications and LED fabrication.