The effects of size and europium concentration on photoluminescence properties of La 2 O 2 S: Eu 3+ nanocrystals (∼20 nm) and the corresponding bulk were studied. The results indicate that in nanocrystals, the absorption edge largely shifted to blue in comparison to the bulk, which was mainly attributed to the variation of phononexcitation relaxation. Two excitation bands were observed, located at ∼250 and ∼330 nm, respectively, corresponding to the charge transfer (CT) transitions of Eu-O and Eu-S. Relative to the CT transition of Eu-O, that of Eu-S increased greatly with europium concentration. The dependence of photoluminescence intensity on concentration showed that in the nanocrystals and the bulk, Eu 3+ ions had two different quenching mechanisms, respectively, the exchange interaction and electric dipole-dipole interaction.

Three-dimensionally ordered macroporous (3DOM) ZrO 2 :Eu 3+ inverse opal materials prepared by polystyrene (PS) colloidal crystal templating, using the sol-gel method, were successfully fabricated. Their crystal structure, morphology, and photoluminescence (PL) properties and the effect of the photonic stop-band on the spontaneous emission of Eu 3+ ions were studied and compared with those of the nonporous sample. In the 3DOM ZrO 2 : Eu 3+ , significant suppression for the 5 D 0 -7 F 1 transition peaking at 590 nm was observed, which was in good agreement with the photonic band gap calculated (∼586 nm). After grinding the 3D ZrO 2 :Eu 3+ inverse opal material, the suppression of emission was restored due to the disappearance of the photonic band gap. In the 3DOM ZrO 2 :Eu 3+ , the luminescent lifetime of 5 D 0 -7 F J depended strongly on emission wavelengths, which was mainly attributed to the appearance of different Eu 3+ centers. In the 3DOM ZrO 2 :Eu 3+ , three symmetry sites for Eu 3+ were identified by site-selective excitation, differing from the nonporous sample, in which only one site was identified.

PbWO 4 : Er 3+ ,Yb 3+ nanocrystals (∼100 nm) were prepared by the hydrothermal method at different pH values (pH ) 4, 7, and 9). Their structure and luminescence properties under 978-nm laser-diode excitation were studied. The results indicate that the practical ratio of W to Pb in the nanocrystals and the doping concentration of Yb 3+ depended strongly on the pH value due to structure change. In upconversion, red ( 4 F 9/2 f 4 I 15/2 ) and green ( 2 H 11/2 , 4 S 3/2 f 4 I 15/2 ) emissions were observed, both of which occurred via a two-photon populating process. Biexponential upconversion dynamics were observed, which was attributed to luminescence centers surrounded by different local environments. The intensity ratio of 2 H 11/2 f 4 I 15/2 to 4 S 3/2 f 4 I 15/2 (R HS ) was explored to reveal the local thermal effect under the exposure of the laser diode, showing that the temperature at the exposed spot increased linearly with respect to excitation power density and Yb 3+ concentration.

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Heterobimetallic complex microrods of zinc titanium glycolate acetate hydrate tentatively formulated as Zn2Ti3(OCH2CH2O)4(OCH2CH2OH)5(CH3COO)3·2HOCH2CH2OH·H2O were synthesize by homogeneous precipitation.

The photoluminescence of Ti4+ and Eu3+ in monoclinic ZrO2 was demonstrated for optical thermometry through energy transfer from titanium–oxygen complexes to Eu3+.

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Hexagonal LaF 3 nanoplates have been successfully prepared via a polyol-mediated route with ethylene glycol (EG) as solvent. NaNO 3 , which was introduced into the reaction system as a mineralizer, played an important role in the formation process of these nanoplates. The size of the as-prepared nanoplates could be tuned by changing the NaNO 3 content and the NH 4 F content. A possible formation mechanism of these nanoplates has been proposed. The effects of other alkali metal nitrates (LiNO 3 , KNO 3 , RbNO 3 and CsNO 3 ) and solvents (water, methanol, diethylene glycol, and glycerol) on the products have also been explored. The increased chemical potential caused by the addition of NaNO 3 in the reaction system made LaF 3 nanoplates formed initially unstable and transform into stable regular hexagonal LaF 3 nanoplates with a bigger size by a slow dissolution-recrystallization process.