High-efficiency thermoelectric materials require a high conductivity. It is known that a large number of degenerate band valleys offers many conducting channels for improving the conductivity without detrimental effects on the other properties explicitly, and therefore, increases thermoelectric performance. In addition to the strategy of converging different bands, many semiconductors provide a...

A three-dimensional elemental carbon kagome lattice, made of only fourfold-coordinated carbon atoms, is proposed based on first-principles calculations. Despite the existence of 60° bond angles in the triangle rings, widely perceived to be energetically unfavorable, the carbon kagome lattice is found to display exceptional stability comparable to that of C(60). The system allows us to study the...

We introduce a method for directly imaging depletion layers in operando with elemental specificity and chemical speciation at sub-100 nm spatial resolution applicable to today's three-dimensional electronic architectures. These typically contain complex, multicomponent designs consisting of epitaxial heterostructures, buried domains, or nanostructures with different shapes and sizes. Although t...

The influence of nitrogen excess on the optical response of N-rich Cu3N films is reported. The optical spectra measured in the wavelength range from 0.30 to 20.00μm have been correlated with the elemental film composition which can be adjusted in the nitrogen atomic percentage (at%) range from 27 ± 2 up to 33 ± 2. The absorption spectra for the N-rich films are consistent with direct optical tr...

Understanding the properties of surfaces of solids and the interactions of atoms and molecules with surfaces has been of extreme importance both from technological and academic points of view. The recent advent of ultrahigh vacuum technology has made microscopic studies of well-characterized surface systems possible. The way atoms move to reduce the energy of the surface, the number of layers o...

Dry etching is one of the elemental technologies for the fabrication of optical devices. In order to obtain the desired shape using the dry etching process, it is necessary to understand the reactivity of the materials being used to plasma. In particular, III-V compound semiconductors have a multi-layered structure comprising a plurality of elements and thus it is important to first have a full...

2014 In this second part, the mechanical behaviour of elemental semiconductors (ESC) and III-V compounds (CSC) is briefly reviewed. The marked temperature dependence of the stress-strain curve is recalled first and some attention is paid to the correlation between the lower yield stress and dislocation dynamics at moderate temperatures. In Si, some suitable pre-strain yields a very favourable s...

Germanium (Ge), as an elemental semiconductor material, has been an attractive candidate for manufacturing semiconductor microelectronic device. In the present investigation, to improve the biocompatibility of Ge-based device, graphene film is directly deposited on the Ge surface with different coverage area by controlling the growth time. Compared to bare Ge, the presence of graphene film enti...

The scale of environmental impacts associated with the manufacture of microchips is characterized through analysis of material and energy inputs into processes in the production chain. The total weight of secondary fossil fuel and chemical inputs to produce and use a single 2-gram 32MB DRAM chip are estimated at 1600 g and 72 g, respectively. Use of water and elemental gases (mainly N2) in the ...