Transparent and electrically conductive composite silica films were fabricated on glass and hydrophilic SiOx/silicon substrates by incorporation of individual graphene oxide sheets into silica sols followed by spin-coating, chemical reduction, and thermal curing. The resulting films were characterized by SEM, AFM, TEM, low-angle X-ray reflectivity, XPS, UV-vis spectroscopy, and electrical conductivity measurements. The electrical conductivity of the films compared favorably to those of composite thin films of carbon nanotubes in silica.

The optical properties of focused ion beam-engraved, perfectly aligned and spatially controlled multi-quantum-well (MQW) InGaN/GaN nanopillars were investigated. Crystalline MQW nanopillars with a diameter of 30-95 nm and high aspect ratios (7 : 1-16 : 1) showed a maximum of three-fold enhancement in emission intensity per unit active area. A light-emitting contour map of Taiwan is drawn with a nanopillar structure to demonstrate the site control of the technique adopted in the present study. Raman scattering studies were used to characterize the newly created surfaces. Unknown peaks in GaN and InGaN nanostructures are identified for surface optical (SO) phonon modes with proper assignments of wave vectors using multiple excitations, and the SO mode for the ternary phase is reported for the first time.

We report on a new technique for the fast fabrication of well defined arrays of Si islands by means of a stigmated Ga + focused ion beam without masks, resists or etching. Stigmating and defocusing the ion beam resulted in the direct formation of Si islands of different shape and size. The ordering of the island arrays was determined by the pattern of the beam scanning, and in this way nanometre-sized Si island arrays with hexagonal symmetry were accordingly produced. The effects of beam spot distortion and broadening on the milled structure are also examined by scanning electron microscopy imaging. With this technique, not only is the fabrication time shorter, but also the arrangement of the island arrays is possibly controllable.

The focused ion beam direct-written InGaN/GaN multiple-quantum-well nanopillars display strong cathodoluminescence emission blue-shifted by 35 meV compared with that of the as-grown wafer. With the removal of ion-irradiation-damage layers, the emission intensity even increased by a factor of 15. The ion beam induced nanopillar swelling was deliberately enhanced by tuning the beam condition, and the swollen volume can also be easily removed by wet-etching using KOH solution. The swelling behavior of an InGaN/GaN nanopillar under focused ion beam milling is found to play an important rule in reducing pillar size.