Chemical, Structural and Optical Properties of ē-Beam Evaporated Tungsten Diselenide Polycrystalline Thin Film

Polycrystalline thin films of tungsten dieseline were prepared by using rarely reported technique of electron beam evaporation for transition metal dichalcogenides. High purity (99.999 %) reacted compound was used as starting material for the preparation of WSe2 thin films. Various parameters and conditions are outlined which were used for deposition of thin films. The prepared films were characterized using EDAX spectrum, X-ray diffraction, Electron diffraction, Scanning electron microscopy and optical absorption spectroscopy methods. The as grown films were found to be partially transparent, uniform and well adherent. Uniformity was confirmed by SEM. WSe2 film was found in stoichiometric proportion. XRD pattern as well as TEM images revealed the fact that the deposited films are polycrystalline in nature having hexagonal structure. From the study of optical absorption spectra it is found that the prepared films show direct allowed transition with optical band gap of 1.89 eV. The results are in good agreement with the earlier published data of WSe2 thin films deposited by different techniques. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2959

Temperature dependent I-V characteristics of Ag/p-Sn0.2Se0.8 thin film Schottky barrier diode

Ag/p-Sn0.2Se0.8 Schottky barrier diodes have been fabricated and characterized by the current-voltage (I-V) technique as a function of temperature in the range of 303 K to 403 K. The forward bias characteristics have been analyzed on the basis of thermionic emission (TE) theory and the characteristic parameters of Schottky barrier diode such as barrier height, ideality factor and series resistance have been determined. The conventional Richardson plot was drawn and the value of Richardson constant was determined using the intersection of Ln(I0/T2) vs 1000/T. It is found to be around 15 Acm – 2K – 2 which is closer to the reported value for SnSe. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2212

MoSe2 / polyaniline solar cells

Solar cells have been investigated since long for harnessing the solar energy. During this decade, a new direction has come up where in the polymers have been used in the fabrication of solar cells. Polyaniline is one of the polymers which has shown potential for its applications in heterostructure solar cells. This material is being used along with the semiconductors like InSe, TiO2, Si etc. to form the photosensitive interface. In this direction, we report our inv estigations on the use of Molybdenum diselenide (MoSe2) as photosensitive semiconducting material in MoSe2 / polyaniline solar cells. In this paper, the preparation of MoSe2 / polyaniline solar cells has been reported. Also, the photovoltage ® photocurrent characteristics of this structure have been discussed in detail in this paper. The variation of different parameters of MoSe2 / polyaniline solar cells (like open circuit voltage, short circuit current, photoconversion efficiency and fill factor) with the intensity of incident illuminations has been reported in this paper. In present case, the photocurrent density was found to be around 250 μA/cm2 with the photovoltage around 8.5 mV (which is low) the photoconversion efficiency was found to be around 0.7 % along with the fill factor around 0.33. The efforts have been made to explain the low values of the photoconversion efficiency. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2209

Metal-semiconductor field-effect transistors fabricated using DVT grown n-MoSe2 crystals with Cu-Schottky gates

Metal-semiconductor field-effect transistors (MESFETs) based on DVT grown MoSe2 crystals and Cu Schottky gate have been fabricated and studied. When Schottky gate voltage (Vgs) changes from 0 to 10 V, the source-drain current (Ids) increases exponentially with Vgs and the conductance shows a drastic increase with positive Vgs. The fabricated n-MoSe2 MESFET have a saturated current level of about 100 mA and maximum transconductance of about 53 mA/V. Their results suggest a way of fabricating MESFETs from layered metal dichalcogenide semiconducting materials. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2207

Phenomenology of the Heavy Flavored spin 3/2 Baryons in Light Cone QCD

Motivated by the results of the recent experimental discoveries for charm and bottom baryons, the masses and magnetic moments of the heavy baryons with $J^P=3/2^+$ containing a single heavy quark are studied within light cone QCD sum rules method. Our results on the masses of heavy baryons are in good agreement with predictions of other approaches, as well as with the existing experimental data.Comment: 12 Pages, 18 Figures and 3 Tables. Based on: arXiv:0807.3481v2 [hep-ph](Nucl.Phys.B808:137-154,2009). To be Published in the Proceeding of the International Conference on New Trends in High Energy Physics, 27 Sept.-4 Oct. 2008, Yalta, Crimea, Ukrain

Synthesis and Photodetection Properties of Sonochemically Exfoliated Cu0.2Sn0.8Se Nanoparticles

Transition metal chalcogenides (TMCs) with atomically minute structure have shown excessive potential for their optoelectronics field applications and their counterparts. TMCs unique layer dependent properties have pinched increasing consideration of scientists. Here, the high yield synthesis of atomically minute Cu0.2Sn0.8Se nanoparticles has been reported. The nanoparticles are synthesised by sonochemical exfoliation technique. The exfoliated Cu0.2Sn0.8Se nanoparticles have orthorhombic lattice structure which is confirmed from powder X-ray Diffraction with Pnma space group. The lateral morphology of the assynthesized nanoparticles examined under transmission electron microscopy showed them to be of uniform spherical shape. The selected area electron diffraction showed a spot pattern stating the particles to be single crystalline. Moreover, the photodetector based on Cu0.2Sn0.8Se nanoparticles thin film is fabricated. The periodic 670 nm laser illumination of power intensity 3 mW/cm2 is used to study the detector properties. The enhanced photo responsivity and specific detectivity is observed along with fast response. The outstanding detection properties are revealed from the responsivity, specific detectivity, and external quantum efficiency (EQE) of Cu0.2Sn0.8Se nanoparticles-based photodetector

A rat model against chemotherapy plus radiation-induced oral mucositis

AbstractObjectivesPresent study was aimed at developing an experimental model of oral mucositis in rats using a combination of chemotherapeutic agent and radiation.Study designFemale Wistar rats (150–200g) were divided into 3 groups (n=6). Rats in group 1 (normal control) and group 2 (mucositis control) were treated with vehicle. Rats in group 3 were treated with l-glutamine (1g/kg, p.o.; 15days) before and after mucositis induction. Oral mucositis was induced by busulfan (6mg/kg, p.o.; 4days) and the tongue exposed to infrared (IR) radiation of intensity 40mV/cm2 for 5 s on the 1st, 4th and 10th days of challenge using a tail flick apparatus. Parameters monitored were body weight, food intake, blood count and survival. Oral mucositis score (OMS) was recorded daily. Histological changes of the irradiated tongue were assessed by hematoxylin and eosin staining.ResultsBusulfan and IR radiation significantly reduced body weight and food intake of the mucositis control group as compared to normal control. Clear ulceration of the tongue reflected in the OMS. Histopathology of the tongue revealed intense lymphocytic infiltration, decreased thickness of squamous epithelial cell layer, decrease in number of blood vessels, and necrosis of cells along with pseudo-membrane formation in the mucositis control group. These findings suggested that oral mucositis was successfully induced and treatment with l-glutamine partially reversed these conditions.ConclusionOral mucositis was established successfully in rats by the combination of chemotherapeutic agent and IR radiation. This may be a useful model for screening drugs in the treatment of oral mucositis

Surfactant Free Synthesis and Study of Vanadium Pentoxide Nanostructure

The varied oxidation state and layered structure are two importance features of vanadium pentoxide which makes it more special. Here, vanadium pentoxide nanostructure has been synthesized by a surfactant free and ecofriendly method using ammonium vanadate as a precursor salt. Synthesized nanostructure were characterized using X-ray diffraction method (XRD), Energy Dispersive X-Ray Analysis (EDAX), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy to study its structural, compositional, morphology, vibrational modes and optical behavior. XRD and FTIR confirm the orthorhombic phase of the vanadium pentoxide with a layered structure of irregular plates as observed from the SEM micrograph. Moreover, the band gap of material is 2.13 eV as evaluated from UV-Visible data

Physical Characteristics of Al/n-CdS Thin-Film Schottky Diode at High Temperatures

Cadmium sulphide (CdS), a member of group II-VI semiconductors, is a promising material based on its applications. The present investigations describe the preparation and electrical characterization of CdS thin films. CdS thin films with thickness of 1000 nm were deposited by vacuum evaporation at room temperature. Characteristic parameters of Schottky junctions formed by a thermal vapor deposition of 500 nm of Al films on pre-coated CdS glass substrates were obtained experimentally from the I-V characteristics in the temperature range of 303–393 K. Diode parameters, such as the zero-bias barrier height ?b0, flat band barrier height ?bf, ideality factor ?, and series resistance RS were investigated using the thermionic emission method

Deposition and Characterization of Indium Selenide Thin Films for Opto-electronic Devices

Amongst all the III-VI semiconductors, ones that crystallize with a layered structure have gained special interest due to its significant usage in photovoltaic devices. III-VI layered semiconductor such as InSe has low density of dangling bonds on its surface therefore it is considered as vital material for the fabrication of opto-electronic devices like photo sensor, solar cell etc. In present work, InSe thin films were fabricated through a simple and facile drop-casting method, where the thin films were drop-casted between two silver paste electrodes on a glass substrate. The structural, surface morphological, compositional, electrical and optical properties of the prepared films were obsrved by XRD, SEM, EDAX, high precision digital multi-meter and UV-visible spectroscopy, respectively. XRD analysis of the prepared film shows the existence of nano-crystalline nature with monoclinic crystal structure of InSe. SEM images show good continuity of InSe film. InSe thin films are n-type with bandgap of 1.8 eV and their electrical conductivity is in the order of 10 – 10 S/cm that makes them appropriate for using as an absorber layer in the solar cell