Abstract:The structure and thermal behavior of long-chain cycloalkanes (CH2) n with n = 48, 72, 96,144 and 288 have been investigated by electron diffraction, WAXS and SAXS analysis. Five different modifications have been characterized by their subcells as a function of ring size, crystallization conditions and temperature. The rings adopt, in all modifications, a conformation with two straight stems connected by folds. Similarity with the polyethylene lattice is achieved only for n > 144. In this case, the stems are perpendicular to the layer surface and pack in the well-known orthorhombic subcell regardless of whether the rings are crystallized from solution or melt. (CH2)96 forms the same type of subcell when crystallized from the melt, but the stems are oblique to the layer surface. Rings of all sizes undergo a transition into a phase in which the stems are arranged similarly as in the "rotator phase" of linear paraffins. (CH2)72 and (CH2)96 exhibit additional transitions at lower temperatures. One significant feature of some transitions is the change of conformation and length of the folds.
Nanocrystalline p–n junction diodes have been fabricated by using the metal-induced lateral crystallization (MILC) method, in which the Ni films were used to induce amorphous silicon into nanocrystalline. The effects of various thicknesses of Ni films on the material and electrical properties of the p–n junction diodes have been studied in detail. We found that the MILC films induced by 20 nm thick Ni exhibited the best crystallization, with an average grain size of 43.2 nm. The nanocrystalline p–n junction diodes prepared by this process demonstrated a low turn-on voltage of 0.44 V and a very high rectification ratio of 5469 at a
±2V
bias voltage. Thus, our developed p–n junction diodes are applicable in a solar cell. The current mechanism was dominated by the diffusion and recombination as a result of defect centers, caused by Ni-silicides, existing at the interface of the p–n junction diodes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.