C. Venkateswaran

Bio: C. Venkateswaran is an academic researcher from University of Madras. The author has contributed to research in topics: Thin film & Magnetization. The author has an hindex of 18, co-authored 96 publications receiving 1198 citations. Previous affiliations of C. Venkateswaran include Presidency University, Kolkata & SRM University.

Spray deposition and characterization of nanostructured Li doped NiO thin films for application in dye-sensitized solar cells.

Abstract: Transparent conducting Li (0-5 wt%) doped NiO thin films with preferential growth along the (111) plane were deposited onto glass substrates by pyrolytic decomposition of nickel nitrate and lithium chloride precursors at 500 °C in air. The effect of Li concentration on the structural, optical and transport properties of NiO thin films was studied by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectral transmittance, photoluminescence and linear four-probe resistivity. Activation energies as a function of Li concentration were deduced from the temperature dependent resistivity data measured in the range 300-448 K. The figure of merit was deduced by combining the spectral transmittance and sheet resistance values. The variation in properties of NiO thin film due to Li doping are discussed based on the above results. A dye-sensitized solar cell has also been fabricated for the optimized Li doped NiO thin film and the results are presented.

Spray deposition and characterization of nanostructured Li doped NiO thin films for application in dye-sensitized solar cells

Abstract: Transparent conducting Li (0–5 wt%) doped NiO thin films with preferential growth along the (111) plane were deposited onto glass substrates by pyrolytic decomposition of nickel nitrate and lithium chloride precursors at 500 ◦C in air. The effect of Li concentration on the structural, optical and transport properties of NiO thin films was studied by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectral transmittance, photoluminescence and linear four-probe resistivity. Activation energies as a function of Li concentration were deduced from the temperature dependent resistivity data measured in the range 300–448 K. The figure of merit was deduced by combining the spectral transmittance and sheet resistance values. The variation in properties of NiO thin film due to Li doping are discussed based on the above results. A dye-sensitized solar cell has also been fabricated for the optimized Li doped NiO thin film and the results are presented.

Room temperature ferromagnetism in vacuum annealed ZnFe2O4 nanoparticles

Abstract: We report room temperature ferromagnetism in vacuum annealed ZnFe2O4 (ZFO) nanoparticles. Upon vacuum and air annealing, ZFO nanoparticles show ferro and paramagnetic behavior, respectively. The well defined sextets along with doublet seen in the Mossbauer spectra confirms ferromagnetic coupling in vacuum annealed ZFO. After reannealing in air, the magnetization of vacuum annealed sample reduces from 62 to 1.5 emu/g. Both Mossbauer and micro-Raman results suggest that oxygen vacancies generated during vacuum annealing causes cation redistribution between the interstitial sites resulting in magnetic ordering. Our results show a unique possibility of switching the magnetic properties of ZFO between paramagnetic to ferromagnetic.

Molybdenum Oxides – From Fundamentals to Functionality

Abstract: The properties and applications of molybdenum oxides are reviewed in depth. Molybdenum is found in various oxide stoichiometries, which have been employed for different high-value research and commercial applications. The great chemical and physical characteristics of molybdenum oxides make them versatile and highly tunable for incorporation in optical, electronic, catalytic, bio, and energy systems. Variations in the oxidation states allow manipulation of the crystal structure, morphology, oxygen vacancies, and dopants, to control and engineer electronic states. Despite this overwhelming functionality and potential, a definitive resource on molybdenum oxide is still unavailable. The aim here is to provide such a resource, while presenting an insightful outlook into future prospective applications for molybdenum oxides.