Switchable multi-color light emitter based on Eu-implanted SiO2 layers confined in a MOS structure

Si based light emitter become more and more important for the integration of optical and electrical function in one and the same chip. Among the various approaches rare earth (RE) implanted SiO2 layers confined in a MOS structure are especially promising due to the well-known optical properties of RE ions, the excellent material properties of the hosting SiO2 matrix and the full compatibility with current Si technology.
Here we report on the switchable multi-color electroluminescence (EL) from a MOS capacity doped with Eu. Depending on the electrical excitation conditions either the red narrow EL originating from a 4f inner shell transition of the Eu3+ ion or the blue broad emission from Eu2+ assigned to a 5d-4f electronic transition is dominant. The behavior of the EL spectrum as a function of the excitation and fabrication conditions is investigated, and the mechanisms behind will be discussed. The Si-based multi-color emitter introduces a new functionality into photonics and shows great potential for future micro-photonic applications.