17 Result(s)

Article

Surface Impregnation of Niobium Alloy in Grinding by Corundum and Silicon-Carbide Wheels

The formation of surface relief after the grinding of a niobium alloy by corundum and silicon-carbide wheels with ceramic binder is considered. A scanning dual-beam electron microscope is used to study the gro...

V. A. Nosenko, A. V. Fetisov, S. P. Kuznetsov, V. G. Karpov in Russian Engineering Research (2022)

Chapter and Conference Paper

Silicon Carbide Crystal Wear Area at Micro-scratching of Zirconium, Niobium, and Molybdenum at a Speed of 60 m/s

Micro-scratching was carried out at a speed of 60 m/s with prepared silicon carbide crystals with preset geometric parameters (cone angle, tip radius). Treated metals: zirconium, niobium, and molybdenum. Morph...

V. A. Nosenko, A. V. Fetisov, V. G. Karpov in Proceedings of the 7th International Confe… (2022)

Article

A numerical model of nonuniform solar cell stability

We model degradation in extended two-dimensional solar cells. The model couples electrical and thermal physics, so that voltage and temperature can vary over a device. Degradation is modeled phenomenologically...

A. C. Vasko, V. G. Karpov in Applied Physics A (2015)

Article

Theory of conductive filaments in threshold switches

We show that the average parameters of conductive filaments and the related characteristics of threshold switches can be described thermodynamically based on the system free energy. In particular, we derive an...

V. G. Karpov, M. Nardone, M. Simon in MRS Online Proceedings Library (2011)

Article

Theoretical and Experimental Study of Shunt Effects in Thin-film Photovoltaics

We present an analytical model that quantitatively describes the physics behind shunting in thin-film photovoltaics and predicts size-dependent effects in theI/V characteristics of solar cells. The model consists...

V. G. Karpov, G. Rich, D. H. Rose, A. V. Subashiev… in MRS Online Proceedings Library (2011)

Article

Theoretical Model of Crystal Nucleation in PCM Nano-Glasses

We propose a theoretical analysis of crystal nucleation in disordered nano-glass structure of chalcogenide phase change memory. Statistical fluctuations of microscopic structure parameters translate into stati...

V. G. Karpov, Y. A. Kryukov, M. Mitra, I. V. Karpov in MRS Online Proceedings Library (2011)

Article

Universal glass dynamics in PCM nano-glasses

The classical double well potential (DWP) model known to explain many phenomena in glasses, is extended to the nano glasses of chalcogenide phase change memory (PCM). We describe simple analytical expressions ...

I. V. Karpov, M. Mitra, D. Kau, G. Spadini, V. G. Karpov… in MRS Online Proceedings Library (2011)

Article

Crystalline Path Formation in Nanoglasses of PCM

This work presents an analytical model of crystalline phase formation in nanoglasses of phase change memory. We describe a data loss mechanism when the cell resistance changes significantly at elevated tempera...

M. Nardone, M. Simon, I. V. Karpov, V. G. Karpov in MRS Online Proceedings Library (2010)

Article

Charge Transport in Nanoglasses of Phase-Change Memory

We discuss possible mechanisms for Poole-Frenkel type of non-ohmic conduction in chalcogenide glasses in the range of room temperatures. Overall, we list 8 such mechanisms, only one of which (Schottky emission...

M. Simon, M. Nardone, S. A. Kostylev, I. V. Karpov… in MRS Online Proceedings Library (2010)

Article

Lateral Nonuniformity And Mesoscale Effects in Giant Area Electronics

The recently developed physics of thin-film photovoltaics is suggested to be representative of other giant area electronics. We show that (i) giant-area devices are intrinsically nonuniform in the lateral dire...

V. G. Karpov, Diana Shvydka, Yann Roussillon in MRS Online Proceedings Library (2005)

Article

Spatial and Temporal Variations in Electronic Transport Through a CdTe-Based Schottky Barrier

We study the electric current through metal-semiconductor junctions of a type used in thin-film PV for back contacts. To concentrate on one type of junction we used the symmetric structures of rf-sputtered CdT...

Diana Shvydka, V. Parikh, V. G. Karpov, A. D. Compaan in MRS Online Proceedings Library (2005)

Article

Physics of CdTe Photovoltaics: from Front to Back

We discuss physical mechanisms underlying the performance and stability of CdTe based thin-film PV. The processes in (i) photovoltaic junction, (ii) back contact, (iii) nonuniformities, (iv) grain boundaries, ...

V. G. Karpov, Diana Shvydka, Yann Roussillon in MRS Online Proceedings Library (2005)

Article

Photoluminescence Fatigue in CdTe Photovoltaics

Junction photoluminescence intensity (PL) in polycrystalline CdTe/CdS solar cells gradually decreases over time, similar to the PL fatigue in chalcogenide glasses. We discriminate between the fatigue per se an...

Diana Shvydka, C. Verzella, V. G. Karpov in MRS Online Proceedings Library (2002)

Article

Organization problems in the production of blood biopreparations

A. K. Barsukov, V. A. Obukhov, O. Yu. Nesterova… in Biomedical Engineering (1996)

Chapter

Fluctuations in Coniferous Taiga Communities

The principal climax types of the Eurasian taiga are coniferous forests consisting of evergreen coniferous trees, such as the species of spruce (Picea abies, P, obovata, P. ajanensis and others), fir (Abies sibir...

A. A. Korchagin, V. G. Karpov in Vegetation Dynamics (1974)

Chapter

Verschiedene Richtungen und Einige Ergebnisse der Experimentellen Untersuchung von Phytozönosen der Dunkelnadelholz-Taiga

Die theoretischen Grundlagen und die Aufgaben der experimentellen Erforschung der Pflanzengesellschaften sind in der letzten Zeit in den Arbeiten von V. N. Sukatschev (1956, 1959, 1964), A. P. Schennikov (1942, 1...

V. G. Karpov in Experimentelle Pflanzensoziologie (1969)