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White-light-emitting diodes are fabricated by using 375nm emitting InGaN chip with Sr3MgSi2O8:Eu2+ (blue and yellow) or Sr3MgSi2O8:Eu2+, Mn2+ (blue, yellow, and red). At a color temperature of 5892K, the color coordinates are x=0.32, y=0.33, and the color rendering index is 84%; at a color temperature of 4494K, the color coordinates are x=0.35, y=0.33, and the color rendering index is 92%. The blue (470nm) and yellow (570nm) emission bands are originated from Eu2+ ions, while the red (680) emiss

The CaMgSi2O6:Eu2+, Mn2+ phosphors show three emission bands peaking at around 450nm (blue), 580nm (yellow), and 680nm (red). The blue band originates from the allowed f-d transition of Eu2+ ions on Ca sites. The yellow and red bands originate from the forbidden T14-A16 transition of Mn2+ ions on Mg2+ and Ca2+ sites, respectively. Electron paramagnetic resonance measurement demonstrates that Mn2+ ions occupy two different Ca2+ and Mg2+ sites. The mixtures of the green-poor CaMgSi2O6:Eu2+, Mn2+ a

Phonon modes of CdSe quantum dots in various glass matrices are investigated by Raman spectroscopy. The phonon energies are observed to be dependent on the host matrix as well as the quantum dot size. We have shown that the lattice contraction effect must be introduced to explain the observed differences of the phonon energies for CdSe quantum dots in the different glass matrices.

The photoluminescence (PL) spectra of Ba 3 MgSi 2 O 8 :Eu 2+ show one peak at 442 nm and two unresolved peaks at 505 nm. The 442 nm peak is attributed to the 4f→5d transition of the Eu 2+ ion doped in the Ba 2+ (I) site with a weak crystal field, while the 505 nm peak originates from Eu 2+ ions on the Ba 2+ (II) or the Ba 2+ (III) site with a strong crystal field. The PL spectra of the Sr 2 SiO 4 :Eu 2+ show two emission peaks at 470 nm and 560 nm. The emission intensity at 470 nm decreases with

Europium -doped alkaline earth orthosilicates , are studied as a phosphor for color-tunable white-light-emitting diode. With an increase of Ba ions in , the lattice constants increase, and the emission bands shift to higher energy in a systematic way. This blueshift behavior can be clarified by crystal field strength. Also, the lattice vibration energies from Raman spectra decrease with an increase of Ba ions in . The emission-quenching temperature dependence of the lattice vibration frequency i