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A. G. Vitukhnovsky

Publications and source records attributed to A. G. Vitukhnovsky.

2 recordsLinked to original sources

Amorphous insulating MoS$_x$ films deposited by magnetron sputtering as a low-index optical coating

While much effort are now concentrated on exploration of crystalline form of MoS$_2$ as a two-dimensional material, we show that room-temperature DC magnetron sputtering from pressurized MoS$_2$ powder target produces amorphous MoS$_x$ films with optical properties fundamentally different from those of crystalline MoS$_2$. The films were found to have a sulfur content of approximately $x=1.8$, indicating sulfur deficiency. They are optically isotropic and exhibit rather low optical losses, with a refractive index of about 2 over the visible and near-infrared spectral range. Their compatibility with lift-off lithography and dry etching makes amorphous MoS$_x$ a promising material for integrated photonic applications.

cond-mat.mtrl-sci↗

Regularities of intermittent luminescence from spherical and tetrapod-shaped quantum dots

Intermittent photoluminescence of colloidal core/shell semiconductor nanocrystals of spherical and branched shape was studied under CW-laser excitation. Luminescent multichannel registration system was applied for the fluorescence detection of single quantum dots (QDs) in the polystyrene matrix. Comparative statistical data were obtained and analyzed for nano-sphere CdSe/CdS and nano-tetrapod CdTe/CdSe crystals. It was found that "on-" and "off-" blinking times are distributed according to the power law both for spherical CdSe/CdS and tetrapod shape CdTe/CdSe samples in spite of significant QD formfactor differences. We have also found that regardless of the QD-shape both successive "on"-times and successive "off "-times are correlated and pointing out to the memory effect in the mechanism of QD re-emission comprising the prehistory of exciton birth and recombination. Pearson-s co-efficients were calculated for the correlations of QD-luminescence behavior. Results of experimental measurements were compared with the peculiarities of relevant phe-nomenon models proposed to date. The data obtained can be used for development of nanophotonic applications and nanocomposite light-emitting materials

physics.optics↗