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

Abstract

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 ∼ 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.