Papers by Keyword: Optical Transmittance

Abstract: The effect of deposition parameters such as sputtering power, nitrogen flow rate and thickness of TaN_x on the optical performance and chemical durability of composite Tantalum nitride /Ag/ tantalum nitride (TaN_x/Ag/TaN_x) films was investigated. When the configuration of composite film was TaN_x (60nm)/Ag (12nm)/TaN_x (60nm) accompanying with the sputtering power 120W and the nitrogen flow rate 50sccm, the visible light transmittance of composite film could reach up to 80% at the wavelength of 550nm and the emissivity was 0.087. In addition, the chemical durability of the coatings was evaluated and the results indicated that the low-e coating presented very good chemical durability.

Abstract: Cuprous oxide films are successfully electrodeposited through the reduction of cupric ions in alkaline and acid electrolytes. The effect of electrodeposition parameters on the optical band gaps of Cu2O films is investigated using UV-vis spectroscopy. It is found that the optical transmittances and the band gaps of the Cu2O thin films are strongly influenced by the electrodeposition bath, the temperature, the current density, and the pH value. The band gaps are varied from 1.80 eV to 2.43 eV with different electrodeposition parameters.

Abstract: Transparent and conductive Al-doped ZnO (AZO) films were prepared by nonreactive DC magnetron sputtering with rapid thermal annealing process. The effects of sputtering power and annealing temperature on growth behavior, electrical rand optical properties of AZO films were investigated. The experimental results show that the sputtering power and annealing temperature had great influence on the electrical resistivity of AZO films due to the change of (002) orientation and grain size. The lowest electrical resistivity of AZO films was 5.3×10-4Ω•cm when the sputtering power was 100W and the annealing temperature was 200°C or above. The sputtering power and annealing temperature had little effect on optical transmittance, which was between 86% and 90%, but the absorption edge had a blue shift with the increase of sputtering power and annealing temperature.

Abstract: In order to prepare translucent sialon more easily, LiF was used as a non-oxide sintering additive to lower the sintering temperature to ≤1650 °C. The present work shows that the sintering process has a strong effect on microstructure and property of α-sialon.

Abstract: AlON with a composition of Al23O27N5 was prepared by hot pressing at temperatures lower than 1900 °C. The microstructures and final properties, including both mechanical properties and optical properties, of the sintered specimens were studied. The results showed that sintering temperature had a great influence on the densification of specimens and could lead to very different properties, especially the optical transmittance and the maximum infrared transmission.

Abstract: In this paper, pure phase Nd-doped YAG powders were prepared by co-precipitation method with different amount of MgO (0~ 0.6 wt %) as additive. Transparent Nd:YAG ceramics were fabricated by vacuum sintering at 1750°C for 10 hours using the powders. Microstructure of the surfaces of thermally etched Nd:YAG ceramics was observed by SEM. Transmittance of the transparent Nd:YAG ceramics was measured over the wavelength region from 600nm to1200nm. The results showed that MgO as sintering aid can restrain abnormal grain growth and reduce pores in grains and at the same time, optical transmittance of the ceramics was increased. The optimal weight percentage of MgO added can be determined as 0.3wt % for the fabrication of transparent Nd:YAG ceramics.

Abstract: SrBi2Nb2O9 (SBN) thin films were prepared on fused quartz substrates at room temperature by pulsed laser deposition. The crystallization behavior and surface morphology were studied at various oxygen pressures by XRD and AFM. The results indicated that the films had polycrystalline structure with a single layered perovskite phase, and exhibited higher crystalline quality, less rough surface morphology, and larger grain size with increasing oxygen pressure. The optical transmittance of the samples was measured in the wavelength range 200-900 nm, and the dispersion relation of refractive indices and wavelength was found to follow the single electron oscillation model. The energy gap of SBN films grown at oxygen pressure of 5 Pa was estimated to be around 3.88 eV by assuming a direct transition between valence and conduction bands.

Abstract: An investigation has been made on the state of barium titanate (BaTiO3; BTO, hereafter) nanoparticles of 10-15 nm in diameter dispersed in various suspension media, such as 2-methoxyethanol (ethylene glycol monomethyl ether: EGMME) with and without acetylacetone (Acac), ethanol, and isopropanol. The state of the nanoparticles dispersed in these suspension media is deduced from the behavior pattern of their optical transmittance (T), in the wavelength (λ) range of 300-900 nm; the concentration (c) of BTO nanoparticles in the suspensions was varied from 0.01 to 0.25 mol/L. T-c plots obtained for EGMME+Acac and EGMME suspensions at various wavelengths indicate that BTO nanoparticles take two and three different states in the suspensions, respectively, from mono-dispersed to agglomerated states with increasing c.

Abstract: Under the simulation environment for the vacuum and heat sink in space, the changes in optical and electrical properties of transparent conductive indium tin oxide (ITO) thin films induced by radiation of protons with 100 keV were studied. The ITO thin films were deposited on JGS1 quartz substrate by a sol-gel method. The sheet resistance and transmittance spectra of the ITO thin films were measured using the four-point probe method and a spectrophotometer, respectively. The surface morphology was analyzed by AFM. The experimental results showed that the electrical and optical performances of the ITO thin films were closely related to the irradiation fluence. When the fluence exceeded a given value 2×1016 cm-2, the sheet resistance increased obviously and the optical transmittance decreased. The AFM analysis indicated that the grain size of the ITO thin films diminished. The studies about the radiation effect on ITO thin films will help to predict performance evolution of the second surface mirrors on satellites under space radiation environment.

Abstract: We synthesized ZnO nanocrystal colloids adopting sol-gel method using zinc acetate dehydrate as precursor, and prepared ZnO films on glass substrates by a spin-coating technique. The effect of annealing temperature on the structure, optical and electrical properties has been studied. The crystallinity and morphologies were improved by the annealing. All film samples show high transmittance of above 80% in the wavelength ranging from 400nm to 1000nm. A minimum resistivity of 5.5x10-3 􀀀
cm was obtained for the film annealed at 500oC. The crystallinity, oxygen vacancies, and nanocrystalline boundaries seems likely to be crucial factors for these properties