Zinc optical properties

Dhas NA, Zaban A, Gedanken A (1999) Surface synthesis of zinc sulfide nanoparticles on silica microspheres sonochemical preparation, characterization, and optical properties. Chem Mater 11(3) 806-813... 

As mentioned above, the conventional diazonium salts have good optical properties as CEL dyes and negative working sensitizers for the two-layer resist system. However, almost all diazonium salts are stabilized with metal-containing compounds such as zinc chloride, tetrafluoroborate, hexafluoro-antimonate, hexafluoroarsenate, or hexafluorophosphate, which may not be desirable in semiconductor fabrication because of potential device contamination. To alleviate the potential problem, new metal-free materials have been sought for. 

The principle uses of the zinc borate Zn[B304(0H)3] are as a polymer additive and preservative for wood composites, such as oriented strand board (OSB). As a polymer additive it functions as a fire retardant synergist and modifier of electrical and optical properties. Its function as a fire retardant additive is discussed further below. A substantial amount of Zn[B304(0H)3] is used to improve the tracking index, which is an important performance criterion for polymers, such as polyamides (nylon) and polybutyl teraphtha-lates (PBT), used in electrical applications. 

Zinc oxide is certainly not unique in exhibiting a strong correlation between adsorption and its electrical and optical properties. 

For optical applications requiring extreme clarity it is desirable to minimize silver streaking, and yellowing. For example, Topas 5013 can be modified pentaerythritol tetrastearate, pentaerythritol distearate, or zinc stearate in order to improve the optical properties (59). These blends are suitable for high precision optical applications. 

Since the first synthesis of mesoporous materials MCM-41 at Mobile Coporation,1 most work carried out in this area has focused on the preparation, characterization and applications of silica-based compounds. Recently, the synthesis of metal oxide-based mesostructured materials has attracted research attention due to their catalytic, electric, magnetic and optical properties.2 5 Although metal sulfides have found widespread applications as semiconductors, electro-optical materials and catalysts, to just name a few, only a few attempts have been reported on the synthesis of metal sulfide-based mesostructured materials. Thus far, mesostructured tin sulfides have proven to be most synthetically accessible in aqueous solution at ambient temperatures.6-7 Physical property studies showed that such materials may have potential to be used as semiconducting liquid crystals in electro-optical displays and chemical sensing applications. In addition, mesostructured thiogermanates8-10 and zinc sulfide with textured mesoporosity after surfactant removal11 have been prepared under hydrothermal conditions. 

Further modification of the coumarin ring system in esculin (1) led to the development of 7-amino-4-methylcoumarins with an A-alkyl group at the 7-position. The sole representative of this series still on the market is 7-diethylamino-4-methylcoumarin (63) [91-44-1] [101], Despite its poor lightfastness, the good optical properties of this compound have kept it in use for the brightening of wool, cellulose acetate rayon, and polyamides. Compound 63 is produced by cyclocondensation of 3-diethylaminophenol with ethyl acetoacetate in the presence of zinc chloride [102],... 

Metal nanoparticles have extraordinary size-dependent optical properties, not present in the bulk metal and have, consequently, been the subject of intense research during the past decade or so.27 Attention has recently focused on functionalising colloidal nanoparticles with molecular recognition components for potential sensing applications.28,29,30 We have prepared a new amido-disulfide functionalised zinc metalloporphyrin (8) which was self-assembled on to gold nanoparticles to produce a novel anion-selective optical sensing system (9) (Scheme 3).4... 

For the description of the linear and nonlinear optical properties of metallotetrapyrroles, TDDFT methods have proven [133-148] to be an excellent alternative to conventional highly correlated ab initio methods, such as SAC-CI, STEOM-CC, and CASPT2, for which these systems still represent a severe computational challenge, especially when transition metals, lanthanides or actinides are involved. The few highly correlated ab initio calculations dealing with the excited state properties of metallotetrapyrroles that have appeared to date only concern magnesium and zinc porphyrins and porphyrazines [149-151]. Application of TDDFT methods to the electronic spectroscopy of a variety of metallotetrapyrroles, including homoleptic and heteroleptic sandwiches, will be illustrated in this section. 

In this chapter some of the presently known optical properties of zinc oxide are reviewed. In particular, the anisotropic dielectric functions (DFs) of ZnO and related compounds from the far-infrared (FIR) to the vacuum-ultraviolet (VUV) spectral range are studied. Thereupon, many fundamental physical parameters can be derived, such as the optical phonon-mode frequencies and their broadening values, the free-charge-carrier parameters, the static and high-frequency dielectric constants, the dispersion of the indices of refraction within the band-gap region, the fundamental and above-band-gap band-to-band transition energies and their excitonic contributions. 

It should be mentioned that zinc oxide is also used between silicon and the metallic contact as a part of the back reflector to improve its optical properties and to act as a diffusion barrier [12,13]. A layer thickness between about 60 and 100 nm is usually sufficient here, and there are no strict requirements for... 

Second order non-linear optical properties have been reported for a variety of TTF donor-acceptor compounds <02T7463> and the palladium complex 84 is a room-temperature semiconductor <02CL936>. Preparation of the zinc and cadmium compounds 85 has been reported <02CC1474> and aromatic fused TTFs such as 86 form thin films with useful electrical properties <02JAP265466>. A ferromagnetic interaction occurs in the salt of a TTF... 

Kim, K. H., Park, K. C. and Ma, D. Y. (1997). Structural, electrical and optical properties of aluminum doped zinc oxide films prepared by radio frequency magnetron sputtering. J. Appl. Phys. 81(12), 7764-7772. 

The optical properties of Pr3+ ions have been studied in various fluoride glasses based on zirconium [31,43,45-47], on indium [31,43,48,49] or on zinc fluorides [48,50]. 

J. P. Kuz mina, V.A. Nikitenko, Zinc Oxide. Production and Optical Properties [in Russian], Moscow (1984). 

Recently, there has been a significant increase of research in the field of zinc oxide. This is mainly driven by its extraordinary electrical and optical properties that enable a variety of applications ranging from piezoelectrical... 

The obtained results allow to study the electronic structure and optical properties of ZnO crystal on the basis of conceptually deeper and more detailed background, than it was previously available on integral reflectivity spectra, and to base theoretical calculations of the properties of zinc oxide upon new foundations. 

Suresh K. S. and James F. C., Optical properties of zinc aluminate, zinc gallate and zinc aluminogallate spinels, J. Am. Ceram. Soc. 81 (1998) pp. 649-654. 

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