UV-Vis Spectrophotometer Measurements Research Articles

Compositional, structural, and optical study of nanocrystalline ZnS thin films prepared by a new chemical bath deposition route

Abstract Zinc sulphide nanocrystalline thin films are prepared by a new chemical bath deposition route on glass and quartz substrates using a weak acidic bath, in which nitrilotriacetic acid acts as a complexing agent and thioacetamide acts as a source of sulphide ions. The thickness of films varied from a few nm to 500 nm. The chemical composition of films was determined by energy dispersive X-ray analyzer and Fourier transform infrared spectroscopy. The films are very close to ZnS stoichiometry and no organic compounds, or Zn(OH)2, or ZnO species were observed as impurities in them. X-ray diffraction indicates that the films have cubic zincblende structure. SEM images showed that the films consisted of small uniform grains (about 40 nm in size) and were free of pinholes. The effect of film thickness on optical properties, band gap energy and the size of nanocrystals were studied by UV–vis spectrophotometer measurements. The films of about 170 nm thickness have high transmittance of about 75% in the visible region.

高周波マグネトロンスパッタリング法により作製した結晶性ＧａＴｅ薄膜の膜構造と光吸収スペクトル

Crystallized thin films of layered semiconductor GaTe were fabricated on silica glass by RF magnetron sputtering in H2 and Ar atmospheres. The structure and optical characteristics of these GaTe films were investigated by X-ray diffraction, atomic force microscope measurements and UV-Vis spectrophotometer measurements. The XRD patterns of the films deposited at substrate temperature up to 600°C in argon gas only showed an amorphours structure. The films fabricated with an H2 and Ar gas mixture were crystallized at a hydrogen mole fraction of more than 1 mol.%. Crystallinity and the orientation of the crystalline films showed a dependence on the hydrogen mole fraction. The photo absorption edges showed a direct transition with an optical gap of 1.57 eV, which was in good agreement with that of single GaTe crystals (1.66 eV). The processes of film deposition and crystallization were strongly affected by the presence of hydrogen.

Electrical and structural analysis of conductive polyaniline/polyimide blends

Conducting films of dodecylbenzenesulfonic (DBSA)-doped polyaniline/polyimide (PANI/PI) blends with various compositions were prepared by solvent casting followed by a thermal imidization process. Electrical and physical properties of the blends were characterized by infrared spectroscopy, an X-ray diffraction technique, thermal analysis, a UV-vis spectrophotometer, a dielectrometer, and conductivity measurements. The blends exhibited a relatively low percolation threshold of electrical conductivity at 5 wt % PANI content and showed higher conductivity than that of pure DBSA-doped PANI when the PANI content exceeded 20 wt %. A lower percolation threshold and a lower compatibility was shown between the two components in the blends than those of PANI–camphorsulfonic acid/polyamic acid (PANI–CSA/PAA). A well-defined layered structure due to the alignment of the long alkyl chain dopant perpendicular to the PANI main chain was evidenced by WAXD spectra. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2169–2178, 1999