Creating a well-defined nanostructure through de-oxyribo nucleic acid (DNA)-nanotechnology, and specifically the development of metal/inorganic semiconductor junctions on DNA-assembled nanostructures, is an emerging research area. Herein, we investigate the electrical properties of biomolecule DNA-template based one-dimensional nanowires (NWs)-CdS/Au and without-template based nanoparticles (NPs)-CdS/Au devices grown on the Indium Tin Oxide (ITO) glass substrates. More importantly, the NWs-CdS/Au device displays a dramatic augmentation of current flow and also a striking change in threshold voltage (~55 mV) in comparison to NPs (~190 mV) and reported bulk-CdS/Au (~680 mV) devices.
View Article and Find Full Text PDFAn innovative scheme to carry out continuous-scan X-ray absorption spectroscopy (XAS) measurements similar to quick-EXAFS mode at the Energy-Scanning EXAFS beamline BL-09 at INDUS-2 synchrotron source (Indore, India), which is generally operated in step-by-step scanning mode, is presented. The continuous XAS mode has been implemented by adopting a continuous-scan scheme of the double-crystal monochromator and on-the-fly measurement of incident and transmitted intensities. This enabled a high signal-to-noise ratio to be maintained and the acquisition time was reduced to a few seconds from tens of minutes or hours.
View Article and Find Full Text PDFOptical coherence tomography (OCT) enables us to monitor alterations in the thickness of the retinal layer as disease progresses in the human retina. However, subtle morphological changes in the retinal layers due to early disease progression often may not lead to detectable alterations in the thickness. OCT images encode depth-dependent backscattered intensity distribution arising due to the depth distributions of the refractive index from tissue microstructures.
View Article and Find Full Text PDFHfO/SiO periodic multilayer high reflection mirrors have been prepared by a reactive electron-beam evaporation technique. The deposited mirrors were annealed in the temperature range from 300°C to 500°C. The effects of annealing on optical, microstructural, and laser-induced damage characteristics of the mirrors have been investigated.
View Article and Find Full Text PDFHfO(2)-SiO(2) mixed composite thin films have been deposited on fused silica substrate by co-evaporation of HfO(2) and SiO(2) through the reactive electron-beam evaporation technique. The composition-dependent refractive index and the absorption coefficient have been analyzed using different effective medium approximation (EMA) models in order to evaluate the suitability of these models for such mixed composite thin films. The discrepancies between experimentally determined and EMA-computed values are explained through microstructural and morphological evolutions observed in these mixed composite films.
View Article and Find Full Text PDFPost nondestructive analyses of an all-dielectric multilayer Fabry-Perot interference filter developed through a reactive electron beam deposition process have been carried out through numerical reverse engineering of transmission spectra, Rutherford backscattering spectroscopy and quartz crystal monitoring data to derive multilayer geometry, deposited layer thicknesses, densities, refractive indices, compositions, and stoichiometry. These techniques are collectively used to fulfill the missing links with complementary and some supplementary information to inverse synthesize the multilayer geometry. During this investigation it is distinctly understood that the factors associated with real-time deposition have significantly influenced the microscopic parameters, namely, the densities and refractive indices of TiO2 and SiO2 layers.
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