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491.
The error rate in complementary transistor circuits is suppressed exponentially in electron number, arising from an intrinsic physical implementation of fault-tolerant error correction. Contrariwise, explicit assembly of gates into the most efficient known fault-tolerant architecture is characterized by a subexponential suppression of error rate with electron number, and incurs significant overhead in wiring and complexity. We conclude that it is more efficient to prevent logical errors with physical fault tolerance than to correct logical errors with fault-tolerant architecture. 相似文献
492.
Dimitri Zielke Jan Hendrik Petermann Florian Werner Boris Veith Rolf Brendel Jan Schmidt 《固体物理学:研究快报》2011,5(8):298-300
Atomic‐layer‐deposited aluminum oxide (AlOx) layers are implemented between the phosphorous‐diffused n+‐emitter and the Al contact of passivated emitter and rear silicon solar cells. The increase in open‐circuit voltage Voc of 12 mV for solar cells with the Al/AlOx/n+‐Si tunnel contact compared to contacts without AlOx layer indicates contact passivation by the implemented AlOx. For the optimal AlOx layer thickness of 0.24 nm we achieve an independently confirmed energy conversion efficiency of 21.7% and a Voc of 673 mV. For AlOx thicknesses larger than 0.24 nm the tunnel probability decreases, resulting in a larger series resistance. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
493.
Alexej Chernikov Swantje Horst Stephan W. Koch Sangam Chatterjee Wolfgang W. Rühle Julian Sweet Benjamin Richards Josh Hendrickson Galina Khitrova Hyatt M. Gibbs Dimitri Litvinov Dagmar Gerthsen Martin Wegener 《Solid State Communications》2009,149(35-36):1485-1492
An ensemble of InAs quantum dots with ground state transition energies centered at 1.216 eV and density 1011dots/cm2 has been studied by time-resolved photoluminescence (PL). The wavelength of the 100-fs excitation pulse was tuned through the ground (excited) state transitions, resulting in resonant (optical phonon sideband) PL. The decay of the PL was time resolved with a streak camera in the interval 1.5–3 ns to avoid scattered laser light. The intensity of the PL was recorded with its polarization both parallel with and perpendicular to the excitation polarization (along one of the crystal’s cleave axes); the ratio is 2.22 at low temperatures and low excitation. A phenomenological rate equation analysis is made, separating the excitations into two classes, one polarized along the excitation polarization and the other unpolarized (either that way immediately after the excitation pulse or scattered from the first class). Excellent fits to the data lead to the conclusion that both classes decay radiatively with a lifetime of 1 ns, and a transfer from the polarized to the unpolarized species takes place with a distribution time of 12 ns at low temperatures and low excitation, dropping rapidly toward zero for temperatures above 30 K and for intense excitation levels. The polarization of a coherently excited ground state exciton should dephase with a rate equal to the sum of the radiative rate plus the inverse of this distribution time. 相似文献
494.
Natalia Gospodinova Dimitri A. Ivanov Denis V. Anokhin Iulia Mihai Loïc Vidal Sulyvan Brun Julia Romanova Alia Tadjer 《Macromolecular rapid communications》2009,30(1):29-33
Films of polyaniline (PANI) featuring about 80% crystallinity and characterised with strong π‐π stacking alignment parallel to the film surface have been obtained directly after the original synthesis upon simple drying of the aqueous PANI suspension. A strong anisotropy in the growth of the nano‐sized crystals produced during the synthesis results in the formation of micrometer‐length fibrils perpendicular to the film surface in the course of water evaporation. The regular intercalation of water molecules between the PANI chains seems to be crucial for their ordering throughout the synthesis and film formation.