Size and temperature dependence of optical properties of Eu 3+ :Sr 2 CeO 4 nanocrystals for their application in luminescence thermometry

Abstract The synthesis of Eu 3+ :Sr 2 CeO 4 nanocrystals prepared by a modified sol–gel method is reported. The nanocrystalline powders were annealed at different temperatures to control the average grain size of nanocrystals. The absorption, emission and excitation spectra of Eu 3+ :Sr 2 CeO 4 nanocrystals were investigated in a temperature range of 10–300 K. In particular the influence of temperature and average nanocrystal size on the optical properties of Eu 3+ :Sr 2 CeO 4 was investigated. It was found that with increasing grain size the luminescence lifetimes significantly decreased. The shortening of lifetimes was extremely strong at elevated temperature. Due to the strong temperature dependence of the f–f and charge transfer (CT) luminescence intensity ratio the Eu 3+ :Sr 2 CeO 4 nanocrystals can be used in the long contact temperature sensing.