Few-layer black phosphorus (BP) is the most promising material among the two-dimensional materials due to its layered structure and the excellent semiconductor properties. Currently, thin BP atomic layers are obtained mostly by mechanical exfoliation of bulk BP, which limits applications in thin-film based electronics due to a scaling process. Here we report highly crystalline few-layer black p...

Searching and designing materials with extremely low lattice thermal conductivity (LTC) has attracted considerable attention in material sciences. Here we systematically demonstrate the diverse lattice dynamics of the ternary Cu-Sb-Se compounds due to the different chemical-bond environments. For Cu3SbSe4 and CuSbSe2, the chemical bond strength is nearly equally distributed in crystalline bulk,...

High-speed melt spinning of a cyclo-olefin polymer (COP) and a copolyamide (CoPA) have been performed. Differential scanning calorimetry curves of the resulting monofilaments show that they remain in an amorphous state even after hot drawing. Wide angle x-ray diffraction patterns of undrawn and drawn COP filaments show that although the material remains in an amorphous state, a degree of orient...

Cosmic dust analogue materials including amorphous and crystalline silicates, ferrous oxide, and iron sulfide have been studied by reflectance spectroscopy of bulk surfaces as well as by transmission spectroscopy of particulates at temperatures down to 10 K. From the reflectance measurements optical data have been derived. The spectra show a sharpening and strengthening of the vibrational bands...

Defect states in different dielectric materials with crystalline and amorphous structures were investigated with two models, the Broer model and the Bloch model. For crystalline structures as in hafnium oxide, defects were found to fit well with the Broer model due to strong local magnetic-field-orientation dependency. In amorphous materials, for example, organosilicate glass, defects were foun...

Periodically poled crystalline materials are extremely attractive for processes such as second harmonic generation and optical parametric generation due to their very high conversion efficiency. For optimal performance, fabrication of poled regions with sub-micron tolerance is required. In this paper we introduce multi-photon laser scanning luminescence microscopy as a powerful minimally-invasi...

The role of liquid crystalline mesophases in polymer crystallization has seen increased attention following the observations of meta-stable liquid crystalline pre-ordering in the crystallization of isotactic polypropylene and other flexible polymers [1–7]. In addition to these recent observations, both in Nature and industry liquid crystal mesophases are used to create polymeric materials with ...

This paper gives an overview of the materials and methods used for fabricating photovoltaic solar cell devices. The technologies discussed include those based on the use of silicon (in the crystalline, multicrystalline, amorphous and micro-crystalline forms), the IIIeV compounds (e.g. gallium arsenide, indium phosphide and gallium antimonide), the polycrystalline compounds (e.g. cadmium telluri...

The recent discovery of topological insulators has revived interest in the band topology of insulators. In this Letter, we extend the topological classification of band structures to include certain crystal point group symmetry. We find a class of three-dimensional "topological crystalline insulators" which have metallic surface states with quadratic band degeneracy on high symmetry crystal sur...

Modifying crystal growth processes using additives is a well established approach to solving problems in many processes. Nature also makes extensive use of crystalline inorganic structures modified by soluble and insoluble organic materials. This Highlight discusses some of the recent and interesting developments in this area, with an emphasis on the control of crystal growth rates, covering bo...