Virudhunagar, India
Virudhunagar, India

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Prithivikumaran N.,Nanoscience Research Laboratory
Journal of Chemical and Pharmaceutical Sciences | Year: 2016

Transparent conducting Cadmium oxide (CdO) semiconducting thin films were deposited by sol ' gel spin coating technique on glass substrates. The structural and electrical properties of the deposited films have been studied with a view to investigate the influence of the annealing time on the different physical properties of the films. The structural studies show that the films are polycrystalline in nature with preferred orientation along the (111) plane. The structural parameters such as crystallite size and strain are obtained from the full width at half maximum (FWHM) values of the diffraction peaks. It has been found that the annealing time has a significant influence on the structural properties of the CdO films. The resistivity of the material decreases and reaches a minimum value at 60 minute annealing time, and then increases for further increase in annealing time. A Polycrystalline CdO film with high conductivity was obtained at an annealing time of 60 minutes.

Prithivikumaran N.,Nanoscience Research Laboratory
Physica B: Condensed Matter | Year: 2016

The CdO, Al doped CdO and Cu doped CdO thin films were coated on p-type silicon substrates by sol–gel spin coating method. The structural, surface morphological and electrical properties of undoped, Al and Cu doped CdO films on silicon substrate were studied. The Ag/CdO/p-Si, Ag/Al: CdO/p-Si and Ag/Cu: CdO/p-Si heterojunction diodes were fabricated and the diode parameters such as reverse saturation current, barrier height and ideality factor of the diodes were investigated by current–voltage (I–V)characteristics. The reverse current of the diode was found to increase strongly with the doping. The values of barrier height and ideality factor were decreased by doping with aluminium and copper. Photo response of the heterojunction diodes was studied and it was found that, the heterojunction diode constructed with the doped CdO has larger Photo response than the undoped heterojunction diode. © 2016 Elsevier B.V.

Samerjai T.,Chiang Mai University | Tamaekong N.,Nanoscience Research Laboratory | Phanichphant S.,Chiang Mai University
Defect and Diffusion Forum | Year: 2012

Undoped WO 3 and WO 3 nanoparticles doped with 0.25-1.0 wt.% Pt were successfully produced in a single step by flame spray pyrolysis (FSP) [1]. Tungsten (VI) ethoxide 5% w/v in ethanol 99.8% and platinum (II) acetylacetonate were used as W and Pt precursors respectively dissolved in ethanol. The undoped WO 3 and Pt-doped WO 3 nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The BET surface area (SSA BET) of the nanoparticles was measured by nitrogen adsorption. From BET measurement, SSA BET increased and d BET decreased with increasing Pt concentration from 0 to 1.0 wt.%. The morphology and accurate size of the primary particles were further investigated by high-resolution transmission electron microscopy (HRTEM). The crystallite size of undoped WO 3 spherical was found to be ranging from 5-20 nm and the crystallite sizes of 0.25-1.0 wt.% Pt-doped WO 3 spherical particles were found to be in the range of 5-20 nm. © (2012) Trans Tech Publications.

Lakshmipriya V.,Nanoscience Research Laboratory | Jeyakumaran N.,Nanoscience Research Laboratory | Prithivikumaran N.,Nanoscience Research Laboratory
International Journal of ChemTech Research | Year: 2014

X-ray diffraction, SEM and FTIR studies were carried out for p-type porous silicon samples, prepared for different etching time by the electrochemical anodization method, to study the influence of etching time on the structural properties of porous silicon layers. The crystalline sizes of porous silicon were determined by XRD data. Decrease insilicon crystalline size with respect to etching time is observed which is due to increase in pore size and porosity. The porosity of the porous silicon samples were determined from the SEM images. The refractive index of porous silicon layers was calculated using effective medium approximation method. Itwasobserved that the porosity is modifiable through etching conditions,which in turn makes refractive index also modifiable. FTIR spectra reveal the formation of SiHn complexesin the porous layer. © 2014, Sphinx Knowledge House. All rights Reserved.

Pandiarajan J.,Nanoscience Research Laboratory | Jeyakumaran N.,Nanoscience Research Laboratory | Prithivikumaran N.,Nanoscience Research Laboratory
International Journal of ChemTech Research | Year: 2014

Tin oxide (SnO2) and porous silicon (PS) are two types of materials that have been extensively investigated for optoelectronic applications. In this work, properties of SnO2 thin film layer deposited on PS by sol-gel spin coating have been investigated. SnO2 was incorporated into the pores of PS and thereby making a protecting layer. XRD result suggests the formation of a good crystalline quality SnO2 tetragonal structure on PS surface and peaks pertaining to PS along with those corresponding to SnO2 were observed. SEM images confirm the pore filling and surface coverage. The covalently grafted inorganic molecules on silicon surfaces are confirmed by transmission FTIR spectra. An enhancement of PL emission has been observed after SnO2 film deposition on PS. From the results, the technique described herein is a cost effective method for producing photoluminescence enhanced SnO2/PS structure that can be used for optoelectronic application.

Bodo B.,Nanoscience Research Laboratory | Kalita P.K.,Nanoscience Research Laboratory
AIP Conference Proceedings | Year: 2010

ZnS thin films are synthesized through chemical bath deposition (CBD) technique from aqueous solution of ZnSO4 and thiourea mixing in equal volume and equimolar ratio. A 1% CuSO4 solution is mixed with the ZnSO4 solution for doping before the final chemical reaction. SEM image shows the formation of mainly nanosheets, teeth and comb like structures. Absorption studies show red shift of enhanced band gap on Cu doping. Photoluminescence of ZnS:Cu reveals the enhancement of blue luminescence at 468nm and low intensity green emission at 493nm which is attributed to more Cu2+ lying in the interstices. XRD shows that the prepared ZnS nanophosphors possess cubic zinc blende structures. © 2010 American Institute of Physics.

Pandiarajan J.,Nanoscience Research Laboratory | Jeyakumaran N.,Nanoscience Research Laboratory | Prithivikumaran N.,Nanoscience Research Laboratory
Advanced Materials Research | Year: 2012

The promotion of silicon (Si) from being the key material for microelectronics to an interesting material for optoelectronic application is a consequence of the possibility to reduce its device dimensionally by a cheap and easy technique. In fact, electrochemical etching of Si under controlled conditions leads to the formation of nanocrystalline porous silicon (PS) where quantum confinement of photo excited carriers and surface species yield to a band gap opening and an increased radiative transition rate resulting in efficient light emission. In the present study, the nanostructured PS samples were prepared using anodic etching of p-type silicon. The effect of current density on structural and optical properties of PS, has been investigated. XRD studies confirm the presence of silicon nanocrystallites in the PS structure. By increasing the current density, the average estimated values of grain size are found to be decreased. SEM images indicate that the pores are surrounded by a thick columnar network of silicon walls. The observed PL spectra at room temperature for all the current densities confirm the formation of PS structures with nanocrystalline features. PL studies reveal that there is a prominent visible emission peak at 606 nm. The obtained variation of intensity in PL emission may be used for intensity varied light emitting diode applications. These studies confirm that the PS is a versatile material with potential for optoelectronics application. © (2012) Trans Tech Publications, Switzerland.

Radhakrishnan A.,Nanoscience Research Laboratory | Rejani P.,Nanoscience Research Laboratory | Beena B.,Nanoscience Research Laboratory
Main Group Metal Chemistry | Year: 2015

In the present study, CuO, polypyrrole (PPy), and CuO/PPy nanocomposites were synthesized to compare the selective adsorption behavior of hazardous metal ions such as Pb(II) ions. The synthesized nanomaterials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller surface area analysis, and energy dispersive X-ray spectroscopy. The adsorption studies clearly showed that CuO/PPy nanocomposites exhibited much higher adsorption performance than individual CuO and PPy. Kinetic data followed the pseudo-second-order model. The equilibrium attained at 120 min and isotherm follows the order Sips>Langmuir>Freundlich. The adsorbed Pb(II) is desorbed using 0.1 m HCl. The adsorption-desorption studies conducted over six cycles illustrate the viability and repeated use of the adsorbent for the removal of Pb(II) from aqueous solutions. The adsorbent's practical efficiency and usefulness were tested using real industrial wastewater, and 0.55 g/L of adsorbent is adequate for the complete removal of Pb(II). Cytotoxicity results show that CuO/PPy nanocomposites were biocompatible at lower concentrations, and they were used as an ecofriendly nanoadsorbent for industrial and environmental applications. © 2015 by De Gruyter 2015.

Sengodan R.,Kumaraguru College of Technology | Chandar Shekar B.,Nanoscience Research Laboratory | Sathish S.,Nanoscience Research Laboratory
Indian Journal of Pure and Applied Physics | Year: 2014

Barium titanate powders were synthesized by the wet chemical method using the starting materials barium chloride (BaCl2), titanium dioxide (TiO2) and oxalic acid with different calcinations temperature. The XRD pattern of BaTiO3 calcined at 500 °C showed cubic phase whereas BaTiO3 samples calcined at 700 °C and above showed tetragonal phase. The crystallite size, strain and dislocation density were calculated from the XRD spectrum. It was found that crystallite size increases with increase of calcination temperature. EDS spectrum was used to identify the composition of the material. Absorption co-efficient (α), extinction co-efficient (K) and optical band gap were estimated from the optical reflectance spectrum. The band gap of the powder was found to be decreasing with the increase of calcination temperature. Nanoparticles of both spherical and rod like in shape were clearly observed in the SEM.

Devadathan D.,Nanoscience Research Laboratory | Raveendran R.,Nanoscience Research Laboratory
IOP Conference Series: Materials Science and Engineering | Year: 2015

In this study single salts of nickel oxide, cobalt oxide, ferric oxide and the nanocomposite of nickel-cobalt-ferric oxide was prepared by the well-known co-precipitation method. The samples were annealed at different temperatures and were characterized using SEM, EDAX, TGA, FTIR, XRD, UV and Photo luminescence (PL). UV analysis showed that the nanocomposite can be suitably tuned to a wide band gap material. The Photo Luminescence analysis showed that the nanocomposite can be used as light emitters in visible region. © Published under licence by IOP Publishing Ltd.

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