Europium activated yttrium aluminate (YAG:Eu) phosphors were synthesized using urea by wet chemical synthesis route. The luminescent behavior and the microstructural changes are monitored, depending on the amount of europium. The luminescent spectra of YAG:Eu phosphors possess four major emission bands in the range of 570–700 nm with maxima situated at 592 nm 598 nm, 611 nm and 631 nm. The intensity ratio between the 611 nm band as red component

Thin PbS films were chemically deposited on glass from alkaline baths containing lead nitrate, thiourea and different additions, such as hydroxylamine hydrochloride, triethanolamine or H2O2. The structural, optical and photoelectrical properties of these films were studied. The main characteristic of films as thick as 0.12–0.54 μm is the photosensitivity. This parameter is influenced by many factors such as film thickness, grain and crystallite

The local environments around mercury atoms in the narrow-bandgap semiconductor alloys have been deduced from extended x-ray absorption fine-structure (EXAFS) analysis. A nonlinear least-squares fitting was applied in order to determine the coordination number, the bond distances and the Debye - Waller factors for the nearest and the next-nearest neighbours around the Hg atom. While ordering has been found for the first coordination shell which consists

CdTe and Hg1-xCdxTe narrow-gap semiconductor materials were deposited as thin films on optical glass, by the laser-assisted physical vapor deposition (LAPVD) process. A pulsed CO2-TEA laser was used to vaporize the studied materials in a vacuum chamber. The Fourier analysis of the (111) CdTe X-ray diffraction profile was used to determine the average effective crystallite size, the root mean square of the microstrain, the stacking fault probability

A sensitization process by heat treatment in oxygen atmosphere was used in order to increase the photoconductivity of vacuum evaporated PbS thin films. The Fourier analysis of the (200) PbS X-ray diffraction profile has shown a decrease of the crystallites mean size and an increase of the sensitized PbS lattice distortion because of chemisorption of oxygen at the crystallites surfaces. The crystallites mean size distribution function indicates that

X-ray absorption fine structure measurements were performed at the Pb L m edge on the oxygen implanted PbS semiconductor thin films in order to probe structural changes in such films. It has been found that the Pb-S bond length was changed from 2.98 A, to 2.82 ,~. The nearest neighbor shell of Pb consists of 5.4 S atoms and 0.60 atoms. The increased values of the Debye-Waller factors indicate the presence of a structural disorder induced by the doping

The production of hydrogen from water using solar light is very promising for generation of an ecologically pure energy carrier. Semiconductor photocatalysts are used to harvest the light energy and induce the hydrogen and oxygen redox reactions. Different types of TiO2 aerogels have been successfully synthesized and the sample with the highest BET surface area was morphologically characterized with the help of SEM measurements. To improve the photoelectrochemical