In this work the role of phase transition of PEO from crystalline to amorphous phases on DC conductivity enhancement in chitosan-based polymer electrolyte was discussed. Silver ion-conducting polymer electrolytes based on chitosan (CS) incorporated with silver nitrate (AgNt) is prepared via solution cast technique. Various amounts of polyethylene oxide (PEO) are added to the CS:AgNt system to prepare blend polymer electrolytes. Ultraviolet-visible (UV-vis) spectrophotometry is used to confirm that the blended samples containing AgNt salt exhibit a broad absorption peak. From optical micrograph images it is apparent that small white specs appear on the surface of the samples. The SEM results clearly show the aggregated silver nanoparticles. The enlargement of the crystalline area was observed from the morphological emergence and impedance plots. The phase separation in SEM images was observed at high PEO concentration. The XRD consequences support the morphological manifestation. In this study a new approach is offered to explore the microstructures existing in the blend electrolytes. The width of the semicircle linked to crystalline phase in impedance spectra was found to be increased with the increase of PEO concentration. A slow increase of DC conductivity was observed at low temperatures while above 333 K an immediate change in DC conductivity was obtained. The rapid rise of DC conductivity at high temperatures is correlated with the DSC results and impedance studies at high temperatures.

Cadmium sulfide (CdS) thin films have been deposited onto glass and polyethylene terephthalate (PET) substrates at room temperature with thermal evaporation in a vacuum of about 3 9 10 -5 Torr for use as window materials for solar cells. Effects of substrate types on the structural and optical characteristics of the films were studied. Sets of experiments were conducted to optimize the deposition of CdS films with appropriate deposition parameters. The deposited films were analyzed with atomic force microscopy, energy dispersive X-ray, X-ray diffraction and optical transmittance measurements to determine their structural and optical characteristics. X-ray diffraction patterns confirm the proper phase formation of the CdS. PET substrate exhibited the larger roughness than that for the glass because of large particles adsorbed on the PET substrate. The average transmittance of the films PET is about 71% and increases up to 81% for glass substrate.

Zinc oxide thin films of different thicknesses ranging from 100 to 300 nm were prepared on polyethylene terephthalate substrates with thermal evaporation in a vacuum of approximately3×10-5Torr. X-ray diffraction patterns confirm the proper phase formation of the material. From atomic force microscopy (AFM) images, it was found that the root mean square roughness of the film surface increased as the film thickness increased. The optical properties of ZnO on PET substrates were determined through the optical transmission method using an ultraviolet-visible spectrophotometer. The optical band gap values of ZnO thin films slightly decreased as the film thickness increased.

ABSTRACT. Lead sulfide (PbS) thin films of different molarities (0.05 M, 0.075 M and 0.1 M) were prepared on glass substrates at 325 0 C by chemical spray pyrolysis (CSP) technique. X-ray diffraction patterns confirm the proper phase formation of the PbS. The X-ray diffraction patterns' results reveal that the all of PbS films have a face centered cubic structure with preferential reflection of (200) plane. The crystallite grain size was calculated using Scherrer formula and it is found that the 0.1M has maximum crystallite grain size (37.4 nm). Depending on the molarity, Hall measurement showed that the electrical resistivity and mobility at room temperature varied in the range 6.3x10 3 Ω.cm to 2.1x10 3 Ω.cm and 4.79cm 2 /V.S to 24.3 cm 2 /V.S.

No abstract

No abstract

Abstract-Lead sulphide (PbS) films were prepared by the chemical spray pyrolysis technique using a solution of Lead nitrate and thiourea. PbS films were deposited (prepared) on glass substrate at varied temperature (250-350 o C). Effects of substrate temperature on the structural characteristics of the films were studied. The X-ray diffraction patterns' results reveal that the all of PbS films have a face centered cubic structure. The X-ray diffraction study showed that irrespective of substrate temperature all the films exhibits a preferred orientation along the (200) plane. The degree of preferred orientation increased with the substrate temperature. It was observed that the increase of the substrate temperature increase the diffraction peak intensity of (200) plane which resulted in increase in grain size and good crystallinity of the films.Index Terms-Chemical spray pyrolysis, lead sulphide, semiconductor, thin film.

No abstract