108 research outputs found
In-situ electrochemical fabrication of natural contacts on single nanowires
We report a template-based in-situ electrochemical method for fabricating
natural electric contacts on single nanowires using a pair of cross-patterned
electrodes. Such electric contacts are highly stable upon thermal cycling
between room temperature and milli-Kelvin temperatures. Direct imaging of the
single-nanowire contacts using scanning electron microscopy is also
demonstrated.Comment: 13 pages, 4 figure
Electrical conduction of silicon oxide containing silicon quantum dots
Current-voltage measurements have been made at room temperature on a Si-rich
silicon oxide film deposited via Electron-Cyclotron Resonance Plasma Enhanced
Chemical Vapor Deposition (ECR-PECVD) and annealed at 750 - 1000C. The
thickness of oxide between Si quantum dots embedded in the film increases with
the increase of annealing temperature. This leads to the decrease of current
density as the annealing temperature is increased. Assuming the Fowler-Nordheim
tunneling mechanism in large electric fields, we obtain an effective barrier
height of 0.7 0.1 eV for an electron tunnelling
through an oxide layer between Si quantum dots. The Frenkel-Poole effect can
also be used to adequately explain the electrical conduction of the film under
the influence of large electric fields. We suggest that at room temperature Si
quantum dots can be regarded as traps that capture and emit electrons by means
of tunneling.Comment: 14 pages, 5 figures, submitted to J. Phys. Conden. Mat
In Situ Imaging of the Conducting Filament in a Silicon Oxide Resistive Switch
The nature of the conducting filaments in many resistive switching systems
has been elusive. Through in situ transmission electron microscopy, we image
the real-time formation and evolution of the filament in a silicon oxide
resistive switch. The electroforming process is revealed to involve the local
enrichment of silicon from the silicon oxide matrix. Semi-metallic silicon
nanocrystals with structural variations from the conventional diamond cubic
form of silicon are observed, which likely accounts for the conduction in the
filament. The growth and shrinkage of the silicon nanocrystals in response to
different electrical stimuli show energetically viable transition processes in
the silicon forms, offering evidence to the switching mechanism. The study here
also provides insights into the electrical breakdown process in silicon oxide
layers, which are ubiquitous in a host of electronic devices.Comment: 7 pages, 7 figure
Realization of an Energetic Hub Based on a High-Performance Dish Stirling Plant
In this work the realization of an energetic hub based on a high-performances dish Stirling system, at the DEIM of the University of Palermo, is presented. The realized system is the first top rated solar thermodynamic plant directly connected to the national electric grid. The connection permits the electricity injection into the grid and allows to access to national renewable energy incentives regime. The system realization was possible thanks to an international cooperation between the University of Palermo and the private company Horizon S.r.l., official partner of Ripasso Energy AB, owner of this technology. Initial data of the plant energy production and the foreseen improvements for the hybridization of the system and its integration with an electrical and geothermal storage system are also presented
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