Measurements of fluorescence intensities in optically thick (lasing) and thin (non-lasing) soluti... more Measurements of fluorescence intensities in optically thick (lasing) and thin (non-lasing) solutions and fluorescence lifetimes of donor in binary mixtures of laser dyes have been made. Various energy transfer parameters such as energy transfer rate parameters, critical transfer radii and mean diffusion lengths for four pairs of dyes have been determined. Fluorescence intensities measured for optically thick solutions were corrected
Dynamics of photo-excited carrier relaxation processes in cadmium selenide nanocrystal thin films... more Dynamics of photo-excited carrier relaxation processes in cadmium selenide nanocrystal thin films prepared by chemical bath deposition method have been studied by nondegenerate femtosecond transient pump-probe spectroscopy. The carriers were generated by exciting at 400 nm laser light and monitored by several other wavelengths. The induced absorption followed by a fast bleach recovery observed near and above the bandgap indicates that the photo-excited carriers (electrons) are first trapped by the available traps and then the trapped electrons absorb the probe light to show a delayed absorption process. The transient decay kinetics was found to be multiexponential in nature. The short time constant,<1 picosecond, was attributed to the trapping of electrons by the surface and/or deep traps and the long time constant,≥20 picoseconds, was due to the recombination of the trapped carriers. A very little difference in the relaxation processes was observed in the samples prepared at bat...
Journal of the Chemical Society, Faraday Transactions, 1996
Formation of radical adducts of Cs0 with alkyl and halo-alkyl radicals ... Transient absorption a... more Formation of radical adducts of Cs0 with alkyl and halo-alkyl radicals ... Transient absorption and emission characteristics of the adducts ... Hirendra N. Ghosh, Haridas Pal, Avinash V. Sapre,* Tulsi Mukherjee and Jai P. Mittal Chemistry Division, Bhabha Atomic Research ...
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013
The surface-enhanced Raman scattering (SERS) studies of anserine (beta-alanyl-N-methylhistidine) ... more The surface-enhanced Raman scattering (SERS) studies of anserine (beta-alanyl-N-methylhistidine) was carried out on colloidal silver nanoparticles to understand its adsorption characteristics. The experimentally observed Raman bands were assigned based on the results of DFT calculations. The studies suggest that the interaction of anserine is primarily through the carboxylate group with the imidazole ring in an upright position with respect to the silver surface. Concentration dependent SERS studies suggest a change in orientation at sub-monolayer concentration.
Measurements of fluorescence intensities in optically thick (lasing) and thin (non-lasing) soluti... more Measurements of fluorescence intensities in optically thick (lasing) and thin (non-lasing) solutions and fluorescence lifetimes of donor in binary mixtures of laser dyes have been made. Various energy transfer parameters such as energy transfer rate parameters, critical transfer radii and mean diffusion lengths for four pairs of dyes have been determined. Fluorescence intensities measured for optically thick solutions were corrected
Dynamics of photo-excited carrier relaxation processes in cadmium selenide nanocrystal thin films... more Dynamics of photo-excited carrier relaxation processes in cadmium selenide nanocrystal thin films prepared by chemical bath deposition method have been studied by nondegenerate femtosecond transient pump-probe spectroscopy. The carriers were generated by exciting at 400 nm laser light and monitored by several other wavelengths. The induced absorption followed by a fast bleach recovery observed near and above the bandgap indicates that the photo-excited carriers (electrons) are first trapped by the available traps and then the trapped electrons absorb the probe light to show a delayed absorption process. The transient decay kinetics was found to be multiexponential in nature. The short time constant,<1 picosecond, was attributed to the trapping of electrons by the surface and/or deep traps and the long time constant,≥20 picoseconds, was due to the recombination of the trapped carriers. A very little difference in the relaxation processes was observed in the samples prepared at bat...
Journal of the Chemical Society, Faraday Transactions, 1996
Formation of radical adducts of Cs0 with alkyl and halo-alkyl radicals ... Transient absorption a... more Formation of radical adducts of Cs0 with alkyl and halo-alkyl radicals ... Transient absorption and emission characteristics of the adducts ... Hirendra N. Ghosh, Haridas Pal, Avinash V. Sapre,* Tulsi Mukherjee and Jai P. Mittal Chemistry Division, Bhabha Atomic Research ...
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013
The surface-enhanced Raman scattering (SERS) studies of anserine (beta-alanyl-N-methylhistidine) ... more The surface-enhanced Raman scattering (SERS) studies of anserine (beta-alanyl-N-methylhistidine) was carried out on colloidal silver nanoparticles to understand its adsorption characteristics. The experimentally observed Raman bands were assigned based on the results of DFT calculations. The studies suggest that the interaction of anserine is primarily through the carboxylate group with the imidazole ring in an upright position with respect to the silver surface. Concentration dependent SERS studies suggest a change in orientation at sub-monolayer concentration.
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