The first series of monodisperse chiral oligofluorenes was synthesized and characterized. Chain length was found to play an important role in solid morphology. Whereas dimer through tetramer are amorphous, pentamer through hexadecamer all show cholesteric mesomorphism with varying degrees of morphological stability against crystallization. Pristine spin-cast films, approximately 90 nm in thickn...

ZnO thin films deposited on various substrates were characterized by slow positron implantation spectroscopy (SPIS) combined with X-ray diffraction (XRD). All films studied exhibit wurtzite structure and crystallite size 20-100 nm. The mosaic spread of crystallites is relatively small for the films grown on single crystalline substrates while it is substantial for the film grown on amorphous su...

In the conventional CdS/CdTe device structure, the poly-CdS window layer has a bandgap of ~2.4 eV, which causes absorption in the short-wavelength region. Higher short-circuit current densities (Jsc) can be achieved by reducing the CdS thickness, but this can adversely impact device open-circuit voltage (Voc) and fill factor (FF). Also, poly-CdS film has about 10% lattice mismatch related to th...

Standard approaches to magneto-mechanical interactions in thermal magnetic crystalline solids involve Landau functionals in which the lattice anisotropy and the resulting magnetization easy axes are taken explicitly into account. In glassy systems one needs to develop a theory in which the amorphous structure precludes the existence of an easy axis, and in which the constituent particles are fr...

A thermodynamic model has been developed which predicts the growth of either an initial (semi-)coherent, strained crystalline oxide phase or an initial amorphous oxide phase (with a possible amorphous-to-crystalline transition) on the bare single-crystalline metal substrate as function of the metal-substrate orientation, the growth temperature and the oxide-film thickness. The model accounts fo...

Morphology evolution of the multicomponent metallic glass film obtained by radio frequency (RF) magnetron sputtering was investigated in the present work. Two modes of metallic glass sputtering were distinguished: smooth film mode and clustered film mode. The sputtering parameters, which have the most influence on the sputtering modes, were determined. As a result, amorphous Ni-Nb thin films wi...

The variety of semiconductor materials has been extended in various directions, for example, to very wide bandgap materials such as oxide semiconductors as well as to amorphous semiconductors. Crystalline β-Ga2O3 is known as a transparent conducting oxide with an ultra-wide bandgap of ~ 4.9 eV, but amorphous (a-) Ga2Ox is just an electrical insulator because the combination of an ultra-wide ban...

Amorphous hydrogenated carbon (a-C:H) films offer a wide range of applications due to their extraordinary material properties like high hardness, chemical inertness and infrared transparency. The films are usually deposited in low temperature plasmas from a hydrocarbon precursor gas, which is dissociated and ionized in the plasma and radicals and ions impinging onto the surface leading to film ...

Whereas the atomic structure of surface of crystals is known to be distinct from that of bulk, experimental evidence for thickness-induced structural transitions in amorphous oxides is lacking. We report the NMR result for amorphous alumina with varying thickness from bulk up to 5 nm, revealing the nature of structural transitions near amorphous oxide surfaces/interfaces. The coordination envir...