Journal of Materials Science: Materials in Electronics

In this novel work, we discuss the effect of neodymium doping concentration on PbS thin films coated on glass substrates by a simple nebulizer spray pyrolysis method. The XRD analysis indicated that all the prepared PbS and PbS:Nd films possess polycrystalline simple cubic crystal structure along (200) preferential orientation and the estimated crystallites size tapered from 21 to 18 nm with growing Nd concentration. It is detected that Raman spectra of all films shows four characteristic mode at 186 cm−1, 281 cm−1, 326 cm−1, and 472 cm−1 certify the formation of PbS thin films. The micrographs obtained from scanning electron microscope indicated uniform particle on the surface of the films. Energy dispersive spectroscopy and mapping analyses confirmed the elemental composition. From the linear optical study by UV–Visible spectrometer exposed the absorption level of all the PbS:Nd films was constantly maintained in the whole visible and IR spectrum which is better for optical device fabrication. The rising of Nd content showed enhancement in band-gap as 2.13 to 2.41 eV. I–V characteristics of all the prepared films were done under dark and illumination conditions. Photosensitivity of the PbS films is enhanced after Nd doping, which result in enhancement of photo current. The results suggest that the proposed strategy can be applied to prepare high-performance photosensitivity thin films.

We have investigated the effect of sulfur concentration ([S]/[Mo] = 0–10 at.%) on nanostructural, optical and electrical properties of MoO3 thin films grown on glass substrate by spray pyrolysis technique. X-ray diffraction analysis showed that the films were crystallized with mixed structures of MoO3 orthorhombic and MoS2 hexagonal structure. According to FESEM images, the studied films have a sponge-type structure on the order of nanometers. Optical measurements revealed that two distinct inflexions indicative two transitions correspond to MoO3/MoS2 phases in agreement with the XRD analysis. The Hall effect and thermoelectric measurements have shown p-type conductivity, and the free hole density increases with increasing sulfur to molybdenum ratio, in agreement with reflectance spectra of the layers. The obtained value of Seebeck coefficient for MoO3 film with [S]/[Mo] ratio of 8 at.% was as high as 169 μV/K.

In this present work, titanium dioxide (TiO2) nanoparticles were prepared by a standard solid-state reaction technique. The structural analysis by the XRD pattern confirms a single rutile phase tetragonal structure. According to scanning electron microscopy analysis, the prepared sample shows uniform morphology with a mean particle size of 120–160 nm. The elemental analyses by energy dispersive spectroscopy confirm the absence of any impurity in the prepared sample. The UV–vis absorption data reveal that the band gap value of the synthesized compound was found to be 2.94 eV. From the optical transmittance spectrum, the average transmittance of the prepared sample in the visible range was found to be 55%. The field and temperature dependence of magnetization reveals a weak ferromagnetic behavior, with saturation magnetization of 0.002 µB and coercivity of 930 Oe. Most likely, the presence of defects and/or oxygen vacancies is thought to be responsible for this particular behavior. Dielectric properties observations reveal that the sample exhibits low dielectric loss in the higher frequency region, which is compatible with the Maxwell and Wagner model.

Sr2+/Ba2+ modified potassium sodium niobate transparent ceramics [(K0.5Na0.5)1−2x(Sr0.75Ba0.25)x]0.93Li0.07Nb0.93Bi0.07O3 (KNNLB:Sr2+/Ba2+) were fabricated via hot-pressing, using Li and Bi as sintering aids. The crystal structure, microstructure, optical, piezoelectric and dielectric properties of KNNLB with varied Sr2+/Ba2+ content were investigated. The optical transparency of such ceramics is up to 60 % in the UV–visible region and close to 100 % in the infrared region. Moreover, the optimum dielectric and piezoelectric performances of ε r  = 1679, d 33 = 151 pC/N and tanδ = 0.026 were obtained for KNNLB:Sr2+/Ba2+ ceramics with x = 0.025. Consequently, the doping of Sr2+/Ba2+ is considered as an effective way to improve electrical properties and maintain excellent optical properties of the fine-grain transparent ceramics.

Results of a study on the application of a copolymer of fluorine as acceptor and 1H-pyrazolo[3,4-b]quinoxaline as a donor in bulk heterojunction solar cells are given. To the best of our knowledge, 1H-pyrazolo[3,4-b]quinoxaline co-polymers were not applied in organic photovoltaic devices yet. Organic photovoltaic devices as well as devices of active layers with TiO2 nanocrystals of different crystallite size were investigated. The methods of polymer and TiO2 nanocrystllites synthesis are presented and their physical properties are given. The fabricated photovoltaic structures possess high values of U oc voltage as as well as relatively high parameters of I sc currents. The maximally achieved parameters corresponded to open circuit voltage U oc  = 1.13[V], and short current density Isc = 33.49[μA] under illumination 1,3 [μW cm−2], which correspond to energy conversion efficiency equal to about 0.80 %. The TiO2 nanocrystallites play a crucial role in the photovoltaics parameters.

Al doped zinc oxide (AZO) thin films were deposited on AZO buffered glass substrates by DC magnetron sputtering. The effect of buffer thickness on the electrical, structural, morphological, and optical properties of the AZO thin films was studied experimentally. As the buffer thickness increased, the resistivity of AZO thin film decreased from 6.4 × 10−4 Ω cm (no buffer) to 3.8 × 10−4 Ω cm (160-nm-thick buffer) and the corresponding mobility increased from 33.4 to 51.2 cm2/Vs,resulting from an improvement of crystallinity. The haze factor of the AZO thin films increased with increasing buffer thickness up to 160 nm, and then slightly decreased. A high average haze factor of 56.7% in the range from 400 to 1100 nm was obtained in the thin film that incorporated a 160-nm-thick buffer, which was attributed to the large feature size of the craters on the surface and the high RMS surface roughness.

One of the main issues confronting researchers is the removal of hazardous organic dyes from industrial effluent. In this work, a biodegradable starch-based polymer (starch-PMA) and silver blend (Ag@starch-PMA) nanocomposite were developed by a free radical process and employed as adsorbents for efficiently removing the hazardous dyes from industrial wastewater. The synthesized polymer adsorbent’s ability to bind to the methylene blue dye in water was tested under optimal conditions. The techniques, including FTIR, indicate the functional groups, TGA/DTG provide the thermal degradation of Ag@starch-PMA (76%) and starch-PMA (90%) at 520 °C and 500 °C, respectively. The surface morphology of the composites was investigated using SEM, and their biodegradation was examined using the soil burial technique. Further, in the adsorption process, parameters like adsorbent dose (0.15 g), pH range (2–12), and dye solution concentration (10 ppm) are optimized. The experimental data indicate the adsorption efficiency of Ag@starch-PMA (95%) and starch-PMA (92%) under the basic pH (8.4–10.4) and further remains constant. The qmax of starch-PMA (522.7834 mg/g) and Ag@starch-PMA (541.2563 mg/g) were assessed by Freundlich adsorption isotherm. In addition, linear fitting kinetic data of starch-PMA (R2 = 0.8619) and Ag@starch-PMA (R2 = 0.9898) showed that the adsorbents follow the pseudo-first order and pseudo-second order of reaction, respectively. A unique adsorbent for the removal of MB dye from an aqueous solution may therefore be found in the resultant nanocomposite.

$${x\hbox{V}_{2}\hbox{O}_{5}\cdot(100-\hbox{x})[\hbox{P}_{2}\hbox{O}_{5}\cdot\hbox{Li}_{2} \hbox{O}]}$$ glass system, with 0  <  x $${\le }$$ 50 mol%, was prepared and investigated by EPR method. For low content of V2O5 all the spectra present a hyperfine structure typical for isolated V4+ ions. With the increasing of V2O5 content, the EPR absorption signal showing hyperfine structure is superposed by a broad line without hyperfine structure characteristic for clustered ions. At high V2O5 content, the vanadium hyperfine structure disappears and only the broad line can be observed in the spectra. Spin Hamiltonian parameters g $$\Vert $$ , g $${\bot}$$ , A $$\Vert $$ , A $${\bot}$$ , dipolar hyperfine coupling parameters, P, and Fermi contact interaction parameters, K, have been calculated.The composition dependence of line widths of the first two absorptions from the parallel band and of the broad line characteristic to the cluster formations was also discussed.