@article { ISI:000272010100009, title = {Optical investigations of interaction between zinc tetra phenyl porphyrin and CdSe nanoparticles}, journal = {Chemical Physics Letters}, volume = {483}, number = {4-6}, year = {2009}, month = {DEC}, pages = {227-232}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Interactions between nanoparticles of zinc tetra phenyl porphyrin (ZnTPP) with CdSe nanoparticles in dimethyl sulphoxide solvent have been investigated. A ZnTPP-CdSe complex was formed which showed substantial changes in the UV-Vis absorption spectra in the presence of CdSe. Fluorescence measurements showed an interesting behavior at low as well as high concentrations of CdSe. When low concentrations of CdSe nanoparticles were added to the ZnTPP nanoparticles solution, besides two fluorescence bands due to ZnTPP nanoparticles, an intense new band appeared. On the other hand at high concentrations of CdSe one of the fluorescence band of ZnTPP at similar to 604 nm increased. (C) 2009 Published by Elsevier B. V.

}, issn = {0009-2614}, doi = {10.1016/j.cplett.2009.10.074}, author = {Lihitkar, N. B. and Singh, S. B. and Singh, Jai and Srivastava, O. N. and Naik, R. H. and Kulkarni, S. K.} } @article { ISI:000303281500046, title = {Confinement of zinc oxide nanoparticles in ordered mesoporous silica MCM-41}, journal = {Materials Chemistry and Physics}, volume = {133}, number = {2-3}, year = {2012}, month = {APR}, pages = {850-856}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Mesoporous silica (MS) and zinc loaded MS composites have been synthesized and characterized using high resolution transmission electron microscopy, X-ray diffraction, UV-visible spectroscopy, photoluminescence spectroscopy, N-2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Thermal treatment of the zinc loaded MS composite lead to the formation of ZnO-MS composite. The well ordered uniform pore structure of MS (pore size similar to 3.4 nm) is found to remain stable even after 30\% Zn loading albeit decrease in the pore size 1.2 nm indicates the formation of ZnO inside the pores. (C) 2012 Elsevier B.V. All rights reserved.

}, keywords = {Defect, Energy spectroscopy for chemical analysis (ESCA), Mesoporous, Photoluminescence spectroscopy, Surface properties}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2012.01.106}, author = {Lihitkar, P. B. and Violet, Samuel and Shirolkar, Mandar and Singh, Jai and Srivastava, O. N. and Naik, R. H. and Kulkarni, S. K.} } @article {44233, title = {High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures}, journal = {AIP Advances}, volume = {8}, year = {2018}, month = {JAN}, pages = {015117}, type = {Article}, abstract = {

The vertical aligned carbon nanotubes (CNTs)-based pillar architectures were created on laminated silicon oxide/silicon (SiO2/Si) wafer substrate at 775 degrees C by using water-assisted chemical vapor deposition under low pressure process condition. The lamination was carried out by aluminum (Al, 10.0 nm thickness) as a barrier layer and iron (Fe, 1.5 nm thickness) as a catalyst precursor layer sequentially on a silicon wafer substrate. Scanning electron microscope (SEM) images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. The CNTs have approximately 2-30 walls with an inner diameter of 3-8 nm. Raman spectrum analysis shows G-band at 1580 cm(-1) and D-band at 1340 cm(-1). The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission analysis of the CNTs revealed high field emission current density (4mA/cm(2) at 1.2V/mu m), low turn-on field (0.6 V/mu m) and field enhancement factor (6917) with better stability and longer lifetime. Emitter morphology resulting in improved promising field emission performances, which is a crucial factor for the fabrication of pillared shaped vertical aligned CNTs bundles as practical electron sources. (c) 2018 Author(s).

}, issn = {2158-3226}, doi = {10.1063/1.5004769}, author = {Gupta, Bipin Kumar and Kedawat, Garima and Gangwar, Amit Kumar and Nagpal, Kanika and Kashyap, Pradeep Kumar and Srivastava, Shubhda and Singh, Satbir and Kumar, Pawan and Suryawanshi, Sachin R. and Seo, Deok Min and Tripathi, Prashant and More, Mahendra A. and Srivastava, O. N. and Hahm, Myung Gwan and Late, Dattatray J.} }