The research on electroluminescence based on europium(III) complexes has come to an important phase. This article reviewed the progresses in photoluminescence and electrohiminescence of Eu(III) complexes in recent years from the views of the design of Eu(III) complexes and optimization of device structures, and discussed some important factors influencing electroluminescence performance. The problems existing in the practical application such as the volatility and thermal stability of Eu(III) complexes in this area were discussed, and the possible corresponding solutions were briefly prospected.
The phosphor Y2SiO5:Ce3+ was prepared by a sol-gel method and the particle growth process was investigated by XRD, SEM and TEM. After heating at 400 °C, the as-dried gel became a powder composed of mixed phases of polycrystalline Y2O3 and amorphous SiO2. With an increase in temperature, the crystallinity of Y2O3 improved. The sample quickly changed to the pure Y2SiO5 phase when it was heated at 1400 °C for 10 min. SEM indicated that the as-dried gel consisted of large porous particles. At an annealing tempe...
Amorphous phosphor 1.4YeO3·2.5Al2O3·0.1Tb2O3 (the same composition as Y2.8Tb0.2Al5O12) was prepared via a sol-gel method at relatively low temperature (i.e., below 650℃), which is much lower than that for the preparation of polycrystalline Y3Al5O12:Tb^3+ (above 1400℃). The amorphous phosphor prepared in the optimized conditions showed a bright green-yellowish luminescence, the intensity of which was comparable with that of polycrystalline sample and the emissions of which were assigned to 5D4 → 7Fj transitions of Tb^3+. Besides the emissions of Tb^3+, the amorphous samples prepared at temperatures below 500 ℃ presented a weak blue emission band around 420 nm.