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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.

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Mn and Cr K X-ray absorption edges were measured in various compounds containing Mn in Mn 2+ , Mn 3+ and Mn 4+ oxidation states and Cr in Cr 3+ and Cr 6+ oxidation states. Few compounds possess tetrahedral coordination in the 1st shell surrounding the cation while others possess octahedral coordination. Measurements have been carried out at the energy dispersive EXAFS beamline at INDUS-2 Synchrotron Radiation Source at Raja Ramanna Centre for Advanced Technology, Indore. Energy shifts of ∼8-16 eV were observed for Mn K edge in the Mn-compounds while a shift of 13-20 eV was observed for Cr K edge in Cr-compounds compared to values in elemental Mn and Cr, respectively. The different chemical shifts observed for compounds having the same oxidation state of the cation but different anions or ligands show the effect of different chemical environments surrounding the cations in determining their X-ray absorption edges in the above compounds. The above chemical effect has been quantitatively described by determining the effective charges on Mn and Cr cations in the above compounds.

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