Various morphologies of Cu 2 S and Cu 2 MoS 4 were synthesized from an octahedral Cu 2 O template in the presence of various concentrations of sodium molybdate and thioacetamide by carrying out solvothermal reactions in an ethylene glycol solvent. The morphology varied from hollow octahedral Cu 2 S structures, through small pieces of P-Cu 2 MoS 4 , and finally to thin square-like plates of I-Cu 2 MoS 4 , depending on the concentrations of sodium molybdate and thioacetamide. The XRD data indicated that the Cu 2 MoS 4 structural phases changed from P42m to I42m the concentrations of sodium molybdate and thioacetamide increased.

Ca 1-x Eu x)Ga 2 S 4 (x = 0.10, 0.40, 0.70, 1.0) phosphors were synthesized from CaS, EuS, and Ga 2 S 3 via a solid-state reaction, and their crystal structures were investigated by X-ray diffraction analysis. Cathodoluminescence (CL) spectra of these phosphors under moderate electron-beam voltages from 4 to 10 kV were investigated to assess their applicability in carbon nanotube field-emission displays. The wavelength at maximum intensity (λ max) of the CL spectra changed gradually from 557 to 546 nm with increasing europium-ion mole fraction (x) in the (Ca 1-x Eu x)Ga 2 S 4 phosphors. These bands were attributed to the transitions from the lowest energy level of the 4f 6 5d 1 excited state to the 4f 7 (8 S 7/2) ground state of the Eu 2+ ions. The blue shift of this wavelength was interpreted on the basis of the crystal structures of the phosphors. The color of light emitted from the (Ca 1-x Eu x)Ga 2 S 4 phosphors was confirmed to be tunable.

Ba 1-x Ga 2 S 4 :xEu 2+ (x = 0.10, 0.25, 0.50, 0.75, 1.0) phosphors were prepared by performing a solid-state reaction. The PL spectra of the Ba 1−x Ga 2 S 4 :xEu 2+ phosphors were recorded. Very broad excitation bands are located in the range 300-480 nm, which suggests that the Ba 1−x Ga 2 S 4 :xEu 2+ can be used as color emission phosphors when pumped with an excitation of 465 nm, which is the wavelength of a commercial blue-emitting diode. The emission wavelength at the maximum PL intensity (λ max ) for the Ba 1−x Ga 2 S 4 : xEu 2+ phosphors increases gradually from 504 to 548 nm as the mole fraction of europium ions (x) in the phosphors increases. The variation in λ max for the Ba 1−x Ga 2 S 4 :xEu 2+ phosphors with the mole fraction of europium ions can be interpreted in terms of the crystal structures of the Ba 1−x Ga 2 S 4 :xEu 2+ phosphors. A three-band white emission was obtained by coating a mixture of Ba 0.5 Ga 2 S 4 :0.5Eu 2+ and CaS:Eu 2+ phosphors onto the surface of a blue-emitting diode.

Cu2O crystals are prepared from aqueous mixtures of CuCl2, TMEDA, D(+)‐glucose, and polyethylene glycol (microwave irradiation, 2 min, ≈46% yield).

Ba0.60MoO4:0.20Eu 3+ ,0.20Na + phosphor is prepared from a mixture of Ba(NO3)2, NaNO3, Eu(NO3)3, (NH4)6Mo7O24, water, sodium oleate, oleic acid, oleylamine, and hexane (autoclave, 80°C, 16 h). A highly transparent suspension is obtained by dispersing the obtained phosphor in toluene. The phosphor exhibits strong absorption at 467 nm, strong emission at 614 nm, and reduced backscattering. It is concluded that the phosphor suspension is a good candidate for red-emitting phosphors for bright emitting three-band white LEDs pumped by a blue LED chip. -(CHO, Y.-S.; HUH*, Y.-D.; Bull. Korean Chem.