Nanostructured Fe₂O₃/TiO₂ composite pigment particles synthesized by a homogeneous precipitation method showed improved NIR reflectance by about 23.8% and about 62.7% larger reflectance at 905 nm than Fe₂O₃.

The light-conversion efficiency of dye-sensitized solar cells (DSSCs) was improved about 13.5% and 6.0% by dispersing a down-conversion phosphor (DCP) and an up-conversion phosphor (UCP) in a TiO₂ layer, respectively. Also, further improvement in the efficiency could be achieved by forming DCP/UCP/TiO₂ double composite layers (η = 8.88%), which is about 21% higher than that of the cell (η = 7.36%) without the phosphor dispersion.

Spray pyrolysis was applied to prepare <mml:math display="inline"><mml:mrow><mml:msub><mml:mi mathvariant="normal">Y</mml:mi><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">Al</mml:mi><mml:mrow><mml:mn>5</mml:mn><mml:mo>−</mml:mo><mml:mn>2</mml:mn><mml:mi>y</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi mathvariant="normal">Mg</mml:mi><mml:mo>,</mml:mo><mml:mi mathvariant="normal">Si</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:mi>y</mml:mi></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>12</mml:mn></mml:mrow></mml:msub><mml:mo>:</mml:mo><mml:mi mathvariant="normal">Ce</mml:mi></mml:mrow></mml:math>Y3Al5−2y(Mg,Si)yO12:Ce phosphors, and the luminescence properties were investigated with changing <mml:math display="inline"><mml:mrow><mml:msup><mml:mi mathvariant="normal">Mg</mml:mi><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:mo>–</mml:mo><mml:msup><mml:mi mathvariant="normal">Si</mml:mi><mml:mrow><mml:mn>4</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>Mg2+–Si4+ content. Boric acid was used to improve the emission intensity and thermal stability. With increasing <mml:math display="inline"><mml:mrow><mml:msup><mml:mi mathvariant="normal">Mg</mml:mi><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:mo>–</mml:mo><mml:msup><mml:mi mathvariant="normal">Si</mml:mi><mml:mrow><mml:mn>4</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>Mg2+–Si4+ content, the emission peak shifted to the longer wavelength, which was explained by the relative strength of the crystal field and covalent character of the host lattice. The largest peak shift was achieved when the <mml:math display="inline"><mml:mi>y</mml:mi></mml:math>y value was 2.0 ( <mml:math display="inline"><mml:mrow><mml:msub><mml:mi mathvariant="normal">Y</mml:mi><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">Mg</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mi mathvariant="normal">Al</mml:mi><mml:msub><mml:mi mathvariant="normal">Si</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>12</mml:mn></mml:mrow></mml:msub><mml:mo>:</mml:mo><mml:mi mathvariant="normal">Ce</mml:mi></mml:mrow></mml:math>Y3Mg2AlSi2O12:Ce , YMASG:Ce) but a significant decrease of the emission intensity was accompanied. Using <mml:math display="inline"><mml:mrow><mml:mn>3</mml:mn><mml:mspace width="0.3em"></mml:mspace><mml:mi>wt</mml:mi><mml:mspace width="0.3em"></mml:mspace><mml:mi mathvariant="normal">%</mml:mi></mml:mrow></mml:math>3wt% boric acid as a flux made it possible to greatly improve the emission intensity of the YMASG:Ce phosphor particles without any deterioration in the temperature dependence. From the investigation on the luminescence characteristics by blending the optimized YMASG:Ce with laboratory-made cerium doped yttrium aluminum garnet (YAG:Ce), the YMASG:Ce/YAG:Ce ( <mml:math display="inline"><mml:mrow><mml:mn>50</mml:mn><mml:mo>∕</mml:mo><mml:mn>50</mml:mn></mml:mrow></mml:math>50∕50 in wt %) mixed phosphor was found to have good emission characteristics favorable to fabricate the warm-white light emitting diodes.

The spray pyrolysis process was applied to prepare oxynitride phosphor , and the luminescence properties were investigated. The prepared particles had a green emission and good excitation characteristics in the region of 400–450 nm. The particles had an oxygen-rich phase . On the basis of the concentration quenching data, the dipole–dipole interaction was dominantly involved in the energy transfer between the ions, and the critical distance was determined to be about . The oxynitride phosphor with a fine size and good luminescent properties could be successfully prepared by the spray pyrolysis.