A Review on High Refractive Index Nanocomposites for Optical Applications

Yuanrong      Cheng; Changli      Lu; Bai      Yang

Abstract

Nanocomposite optical materials with high refractive index (RI) have been one of the most attractive issues due to their good optical property that can be used in many fields. The method for preparing high RI nanocomposites is to incorporate high RI inorganic nano-building blocks, for example, metal oxides and metal chalcogenide semiconductor nanoparticles into polymer matrices. The general design requirements and synthetic methods of these high RI nanocomposites are discussed in this review. We classify the synthetic methods into two parts: in situ particle generation method and ex situ particle generation method, and all the methods are reviewed. Some optical applications on antireflection coatings, volume holographic recording materials, high RI LED encapsulant materials, photonic band gap materials and other applications are also reviewed. The relevant patents are discussed in this article.

Keywords: High refractive index, nanocomposites, nano-building blocks, optical applications, metal oxides, metal chalcogenide, in situ particle generation, ex situ particle generation method, antireflection coatings, volume holographic recording materials, high RI LED encapsulant materials, photonic band gap materials, optical materials, optical waveguides, Fresnel lenses, hologram materials, high molar refractions, Lorentz-Lorenz equation, sulfur-containing aromatic diamines, aromatic dianhydrides, optical resins, impact resistance, organic-inorganic nanocomposites, FABRICATION METHODS, Optical transparency, Rayleigh's law, RI matching method, absorption coefficients, metal oxide, Bohr diameters, irreversible agglomeration, polythiourethane (PTU) oligomers, in situ gas/solid reaction, zirconium alkoxides, titanium alkoxides, sol-gel reaction, copolymerization, UV photoinitiator, dispersibility, compatibility, miscibility, physisorption, Trioctylphos-phine oxide (TOPO), trioctylphosphine (TOP), quater-nary ammonium cation, spin-coating, dip-coating, phosphoric acid, In Situ Polymerization, UV-curing, thermal initiation, Co-Solvent, epoxy resins, mercapto-ethanol (ME), urethanemethacrylate macromer (UMM), capping agent, Phase separation, interfacial interaction, 2-carboxyethyl acrylate (CEA), N, N-dimethylacrylamide (DMAA), -ray irradiation polymerization, ophthalmic lenses, prisms, Antireflection (AR) Coatings, light transmittance, optical filters, solar cells, photodetectors, optoelectronic, reflections hamper device, infrared spectrum, photosensitizer, photopolymerization, photopolymerizable monomers, interference pattern, holographic exposure, holographic data storage, Snell's law, light-extraction efficiency, Photonic band gap (PBG) materials, optical dielectric materials, two-photon lithography, total internal reflection, nonlinear optical (NLO) materials, photochromic, self-cleaning properties