Three stable disilenes, Mes(R)Si=Si(R)Mes where R = mesityl, tert—butyl and (Me3Si)2N, have been prepared by photolysis of trisilanes and dimerization of the resulting ilylenes. X-ray crystallographic studies show Si=Si distances of "215 pm, about 20 pm shorter than for a Si—Si single bond. The silicon and attached carbon atoms are planar in the tert-butylmesityl compound but anti-pyramidal in ...

There are currently great needs to develop low-cost inorganic materials that can efficiently perform solar water splitting as photoelectrolysis of water into hydrogen and oxygen has significant potential to provide clean energy. We investigate the Si/TiO2 nanowire heterostructures to determine their potential for the photooxidation of water. We observed that highly dense Si/TiO2 core/shell nano...

Given S1, a starting set of points in the plane, not all on a line, we define a sequence of planar point sets {Si}∞i=1 as follows. With Si already determined, let Li be the set of all the lines determined by pairs of points from Si , and let Si+1 be the set of all the intersection points of lines in Li . We show that with the exception of some very particular starting configurations, the limiti...

Three-dimensional hierarchical nanostructures were synthesized by the halide chemical vapor deposition of InGaN nanowires on Si wire arrays. Single phase InGaN nanowires grew vertically on the sidewalls of Si wires and acted as a high surface area photoanode for solar water splitting. Electrochemical measurements showed that the photocurrent density with hierarchical Si/InGaN nanowire arrays in...

This work provides a practical application of a coupled experimental–computational system devised for the full characterization of the thermal behavior of complex three-dimensional active submicron electronic devices. A thermoreflectance thermography (TRTG) technique is used to non-invasively measure the 2D surface temperature field of an activated device, with submicron spatial resolution. The...

multiwall carbon nanotubes (mwcnts) are grown via chemical vapour deposition method directly on a stainless steel substrate. raman spectroscopy and transmission electron microscopy are the techniques chosen to characterize the structure of the synthesized carbon nanotubes: few structural defects are detected. after their removal from the stainless steel substrate, the as-grown mwcnts are then a...

In this paper, we study band-to-band and intersubband (ISB) characteristics of Si- and Ge-doped GaN/AlN heterostructures (planar and nanowires) structurally designed to absorb in the short-wavelength infrared region, particularly at 1.55 μm. Regarding the band-to-band properties, we discuss the variation of the screening of the internal electric field by free carriers, as a function of the dopi...

Tetracoordinate planar carbon (that is, carbon atoms coordinated by four other atoms in a square-planar arrangement), first proposed by Hoffmann et al. over thirty years ago, was recently observed in the vibrationally averagedD4h [Al4C] , C2v Al3XC, [Al3XC] (X= Si,Ge), and [CAl4] 2 . Tetracoordinate planar (TP) Si and Ge centers were also discovered in MAl4 and [MAl4] . The TP bonding character...

The progress in silicon planar device technologies has led single-photon avalanche diodes (SPAD) to emerge from the laboratory research phase and be commercially available from various manufactures. QKD systems can already exploit the available planar Si-SPAD devices, but they set strong demand for improved features and performance. A response can be given by new developments in a dedicated sil...

The specular and diffuse reflection properties of sunlight at the rear surface of silicon solar cells with various degrees of roughness are computed by solving the Maxwell and material equations in two dimensions, using the COMSOL RF MODULE. The model is first tested on planar Si/SiO2/air interfaces, where perfect agreement with the Fresnel theory is attained within numerical precision. The cho...