Decay pathway and high-temperature luminescence of Eu3+ in Ca2Gd8Si6O26

The temperature-dependent luminescence of Eu:Ca2Gd8Si6O26 and its decay pathways are investigated in order to assess the utility of the material as a thermometric phosphor. Non-radiative decays are found to compete with radiative processes even at room temperature. A decay pathway involving decay through charge-transfer states is proposed based on the decay profiles of emissions from 5D1 and 5D0 levels and on the temperature sensitivity of the spectra as observed after excitation by several wavelengths. The implications of this on solid-state lighting are also discussed.