Pravin S. More; Dattatray J. Late; Subhash B. Kondawar
Abstract
We report investigations on resistive material SnO2: Cu (9 wt. %) evaluated and optimized for the application of gas sensor. SnO2: Cu has been thoroughly characterized by using X-ray photoelectron spectroscopy (XPS). The deconvolution of XPS spectra confirms the existing surface reactive species in the ...
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We report investigations on resistive material SnO2: Cu (9 wt. %) evaluated and optimized for the application of gas sensor. SnO2: Cu has been thoroughly characterized by using X-ray photoelectron spectroscopy (XPS). The deconvolution of XPS spectra confirms the existing surface reactive species in the form of states of the metal orbital and the presence of multiple pathways for the detection of CO vis-à-vis sintering temperature effect. Enhanced CO pickup at the sintering temperature of 650 0 C (wide range and low sensitivity) and 750 0 C (short range and high sensitivity) has been observed. The CO sensing and XPS data correlates well along with the nonconventional use of variation in average XPS background intensity of general scan seems to be related to optimized sensitivity conditions of various gases.
M. P. Deshpande; Nitya Garg; Sandip V. Bhatt; Pallavi Sakariya; S. H. Chaki
Abstract
Cadmium selenide (CdSe) thin films were prepared by chemical bath deposition technique on glass substrates using cadmium acetate dihydrate as a source of Cd 2+ ions, and sodium selenosulphate as a source of Se 2- ions respectively. Triethanolamine and ammonia were used as complexing and pH controlling ...
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Cadmium selenide (CdSe) thin films were prepared by chemical bath deposition technique on glass substrates using cadmium acetate dihydrate as a source of Cd 2+ ions, and sodium selenosulphate as a source of Se 2- ions respectively. Triethanolamine and ammonia were used as complexing and pH controlling agent. Films were deposited at different bath temperatures ranging from room temperature to 80 o C while the pH value was kept constant around 10.50 ±0.10. We determined elemental composition of deposited film by X-ray photoelectron spectroscopy. Optical properties of films deposited at different bath temperatures are studied by absorption spectra and parameters like thickness, band gap and absorption coefficient were calculated from the optical transmission spectra. The optical spectra showed a small blue shift and the band gap was found to be greater than the bulk phase. Raman measurements performed at room temperature using Helium-neon laser and Argon laser confirmed the presence of longitudinal optical phonon modes. The selected area electron diffraction pattern for CdSe thin films indicated that they are having mixed nature i.e. both single crystalline and polycrystalline nature with planes of diffraction rings corresponding to cubic structure of CdSe respectively.
Indra Sulania; Mushahid Husain;D. K. Avasthi; Dinesh Agarwal; Manish Kumar
Abstract
We present the formation of Ge nanostructures by bombardment of 1.5 keV Ar atoms on Ge (100). The bombardment was carried out at normal incidence with variation in the fluences from 5x10 15 to 3x10 17 atoms/cm 2 . Near surface chemical study on the pristine and irradiated Ge samples has been carried ...
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We present the formation of Ge nanostructures by bombardment of 1.5 keV Ar atoms on Ge (100). The bombardment was carried out at normal incidence with variation in the fluences from 5x10 15 to 3x10 17 atoms/cm 2 . Near surface chemical study on the pristine and irradiated Ge samples has been carried out using X-ray Photoelectron Spectroscopy. In the near surface region of pristine sample, prominence of Ge 4+ was observed by 3d core level present at a binding energy of 33.5 eV. After the irradiation, the evolution of two new core level peaks at binding energies of 29.8 and 30.4 eV confirms the reduction of Ge 4+ to elemental Ge. Atomic Force Micrographs show an increase in surface roughness from 0.4 nm to 10 nm for pristine to sample irradiated at highest fluence. Using the scaling laws and calculating the roughness and growth exponents deduced from Power Spectral Density analysis, it has been found that ion induced coarsening leads to the surface roughening. Further, using the simulation code, it is found that with increasing fluence of bombardment, the deformation of surface starts initially which later on results in simultaneous formation of dots and pits.