Zirconia/phenylsiloxane nano-composite for LED encapsulation with high and stable light extraction efficiency.

To obtain a rapid processible LED encapsulant that leads to high and stable light extraction efficiency (LEE), UV curable ZrO2/phenyl-siloxane nano-composite (ZSC) double-layer encapsulants were prepared and optimized. The highly crystalline ZrO2 nanoparticles with a diameter of ∼14 nm were synthesized through a modified hydrothermal method at mild conditions, and a UV curable methacryl-diphenyl-polysiloxane (MDPS) with a refractive index (RI) of 1.54 (at 633 nm) was synthesized from self-condensation of diphenylsilanediol and an end-capping reaction. High refractive indexes (RIs) from 1.54-1.61 have been obtained for ZSC composites by adding 0-20 wt% ZrO2. Before and after sulfur vapor erosion, the double-layer encapsulated sample (M-10/M) showed 11.2% and 64.8% higher LEE respectively than that of Dow Corning OE-7662. Meanwhile, the variation of LED light color temperature (T c) was less than 1%. The effect of the ZrO2 nanoparticle content on LEE of double-layer and single-layer encapsulation were compared and discussed based on Fresnel loss and Rayleigh scattering theories. The double-layered UV curing processing took only 1/6 of the time needed for common thermal curing.

Improvements of photocurrent by using modified SiO(2) in the poly(ether urethane)/poly(ethylene oxide) polymer electrolyte for all-solid-state dye-sensitized solar cells.

Nanocomposite polymer electrolytes containing poly(ether urethane) (PEUR)/poly(ethylene oxide) (PEO)/modified SiO(2) were prepared for all-solid-state dye-sensitized solar cells with a high efficiency of 4.86% and an active area of 0.25 cm(2) under AM1.5 conditions at 100 mW cm(-2) irradiation.

Synthesis of Low-Viscosity Ionic Liquids for Application in Dye-Sensitized Solar Cells.

Two types of ionic liquids (ILs), 1-(3-hexenyl)-3-methyl imidazolium iodide and 1-(3-butenyl)-3-methyl imidazolium iodide, are synthesized by introducing an unsaturated bond into the side alkyl chain of the imidazolium cation. These new ionic liquids exhibit high thermal stability and low viscosity (104 cP and 80 cP, respectively). The molecular dynamics simulation shows that the double bond introduced in the alkane chain greatly changes the molecular system space arrangement and diminishes the packing efficiency, leading to low viscosity. The low viscosity of the synthesized ionic liquids would enhance the diffusion of redox couples. This enhancement is detected by fabricating dye-sensitized solar cells (DSSCs) with electrolytes containing the two ILs and I2 . The highest efficiency of DSSCs is 6.85 % for 1-(3-hexenyl)-3-methyl imidazolium iodide and 5.93 % for 1-(3-butenyl)-3-methyl imidazolium iodide electrolyte, which is much higher than that of 5.17 % with the counterpart 1-hexyl-3-methyl imidazolium iodide electrolyte.

Photoswitchable and Water-Soluble Fluorescent Nano-Aggregates Based on a Diarylethene-Dansyl Dyad and Liposome.

In this work, a unique approach is developed to generate photoswitchable and water-soluble fluorescent nano-aggregates. Initially, a new light-controlled diarylethene-dansyl dyad DAE 1 is formed by linking two dansyl fluorophores covalently to a symmetrical dithienylethene backbone, whose photophysical properties can be reversibly switched by optical stimuli. Subsequently, the water insolubility of the molecular switch 1 is overcome by incorporating it into the bilayer of liposome DPPC (1,2-dihexadecanoyl-sn-glycero-3-phosphocholine) in water. This strategy creates stable fluorescent nano-aggregates OF-1@DPPC (≈25 nm diameter) that are soluble in an aqueous medium. The nano-aggregates OF-1@DPPC retain and even improve the photoswitchable fluorescence properties of DAE 1. More importantly, OF-1@DPPC exhibits a remarkable photostability and fatigue resistance after 5 cycles of irradiation with UV and visible light, which is crucial for its practical application.

A 7.72% efficient dye sensitized solar cell based on novel necklace-like polymer gel electrolyte containing latent chemically cross-linked gel electrolyte precursors.

Novel necklace-like polymer gel electrolytes containing latent chemically cross-linked gel electrolyte precursors were prepared for quasi-solid dye sensitized solar cells with a highest efficiency of 7.72% and an active area of 0.25 cm2 under AM1.5 condition at 100 mW cm(-2) irradiation.

An iodine-free electrolyte based on ionic liquid polymers for all-solid-state dye-sensitized solar cells.

An ionic liquid polymer, poly (1-alkyl-3-(acryloyloxy)hexylimidazolium iodide), was employed as an iodine-free electrolyte in all-solid-state dye-sensitized solar cells with an overall conversion efficiency of 5.29% under AM 1.5 simulated solar light (100 mW cm(-2)) illumination.