13,055 research outputs found
Process and design considerations for high-efficiency solar cells
This paper shows that oxide surface passivation coupled with optimum multilayer anti-reflective coating can provide approx. 3% (absolute) improvement in solar cell efficiency. Use of single-layer AR coating, without passivation, gives cell efficiencies in the range of 15 to 15.5% on high-quality, 4 ohm-cm as well as 0.1 to 0.2 ohm-cm float-zone silicon. Oxide surface passivation alone raises the cell efficiency to or = 17%. An optimum double-layer AR coating on oxide-passivated cells provides an additional approx. 5 to 10% improvement over a single-layer AR-coated cell, resulting in cell efficiencies in excess of 18%. Experimentally observed improvements are supported by model calculations and an approach to or = 20% efficient cells is discussed
Electro-Reflectance Spectra of Blue Bronze
We show that the infrared reflectance of the quasi-one dimensional
charge-density-wave (CDW) conductor K0.3MoO3 (blue bronze) varies with position
when a voltage greater than the CDW depinning threshold is applied. The spatial
dependence and spectra associated with these changes are generally as expected
from the electro-transmission [B.M. Emerling, et al, Eur. Phys. J. B 16, 295
(2000)], but there are some differences which might be associated with changes
in the CDW properties on the surface. We have examined the electro-reflectance
spectrum associated with CDW current investigation for light polarized parallel
to the conducting chains for signs of expected current-induced intragap states,
and conclude that the density of any such states is at least an order of
magnitude lower than expected.Comment: 1)submitted to Eur. Phys. J B 2) revised (July 24) to a) better
emphasize results and b) with new figure insets to make paper more
self-containe
Forward-Backward Asymmetry in
The Forward-backward asymmetry in the angular distribution of is
studied in the process . The
possibility of observing CP violation through the asymmetries in these two
processes is examined.Comment: 5 pages, latex formatte
The effects of enhanced Z penguins on lepton polarizations in
The sensitivity of the mode to electroweak penguins and the
recent experimental data for the , modes has given rise
to what is known as the `` puzzle''. Recently it has been observed
that this {\sl puzzle} can be resolved by considering the new physics which can
enter via penguins. In this note we analyze the effect of this enhanced
penguins on the lepton polarization asymmetries of .Comment: Published versio
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