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241.
K. E. Avjyan L. A. Matevosyan A. Yu. Mkrtchyan A. M. Khachatryan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2012,47(3):137-141
Optical properties of a-Ge films (glass substrate) and electrical properties of a-Ge/p-Si heterostructures obtained by the pulsed-laser deposition method have been studied. It is shown that optical properties
of a-Ge films can be well explained by the Tauc model for amorphous semiconductors. The dependence of optical gap on the film
thickness is obtained for a-Ge films. Forward-bias current-voltage characteristics of the a-Ge/p-Si heterostructures are satisfactorily approximated by the relation for current density J = CV
m
, where m varies from 1.45 to 1.95 depending on the applied forward bias and a-Ge film thickness. Also, for the mentioned heterostructure
(a-Ge film thickness is 400 nm) nearly quadratic dependence of the current density is observed, which indicates the predominance
of the space-charge-limited current. 相似文献
242.
Florian Audet Dr. Morgan Donnard Dr. Armen Panossian Dr. David Bernier Dr. Sergii Pazenok Dr. Frédéric R. Leroux 《Chemical record (New York, N.Y.)》2023,23(9):e202300107
Sulfuryl fluoride is a gas produced on a multi-ton scale for its use as a fumigant. In the last decades, it has gained interest in organic synthesis as a reagent with unique properties in terms of stability and reactivity when compared to other sulfur-based reagents. Sulfuryl fluoride has not only been used for sulfur-fluoride exchange (SuFEx) chemistry but also encountered applications in classic organic synthesis as an efficient activator of both alcohols and phenols, forming a triflate surrogate, namely a fluorosulfonate. A long-standing industrial collaboration in our research group drove our work on the sulfuryl fluoride-mediated transformations that will be highlighted below. We will first describe recent works on metal-catalyzed transformations from aryl fluorosulfonates while emphasizing the one-pot processes from phenol derivatives. In a second section, nucleophilic substitution reactions on polyfluoroalkyl alcohols will be discussed and the value of polyfluoroalkyl fluorosulfonates in comparison to alternative triflate and halide reagents will be brought to light. 相似文献