Enhancing Blue Emission In Ce Doped Silicon Oxynitrides Based Electroluminescent Devices

Ce-doped SiOxNy and SiAlON matrices are promising materials for blue LED applications. The uniqueness of this approach stems from the fact that SiOxNy, as a host, combines specific properties of individual SiOx and SiNy matrices like solubility, efficient emission, 5 eV gap, with a broad excitation range from 400 nm to 500 nm of Ce3+ ions due to the 4f-5d transitions. Furthermore, the co-doping with aluminum enhances the Ce3+ emission. In this work, we fabricated electroluminescent devices using SiOxNy:Ce3+ and SiAlON:Ce3+ as active layers and investigated the resulting emission under optical and electrical excitations as a function of nitrogen, cerium and aluminum concentrations. I-V measurements were conducted to determine the SiOxNy:Ce3+ layer electrical parameters. Charge transport through the devices obeys the Poole-Frenkel conduction mechanism. It was demonstrated that by optimizing the SiOxNy:Ce3+ growth parameters, an improvement of electroluminescence yield can be achieved with a maximum intensity obtained for devices with cerium content of 4 at.%. (C) 2019 The Electrochemical Society.