Theoretical analysis and Computer simulations have proven to be cost-effective and powerful tools in scientific studies of materials, particularly at nano-scale where synthesis of nano-structures, interpretation of their observed character and exploration of new structures are not always straight forward. We present here fundamental principles of techniques used today for computational simulati...

We study mechanically exfoliated nanosheets of franckeite by quantitative optical microscopy. The analysis of transmission-mode and epi-illumination-mode optical microscopy images provides a rapid method to estimate the thickness of the exfoliated flakes at first glance. A quantitative analysis of the optical contrast spectra by means of micro-reflectance allows one to determine the refractive ...

We study graphene electrodes that can be used for contacting single molecules. The nanometer-scale gap is made by feedback controlled electroburning in few-layer graphene sheets. We analyze the time stability, and the influence of the temperature and gate voltage on the current flowing through the empty gaps. The electrodes are stable at room temperature for long periods of time. We show statis...

High-quality large-sized hexagoal WSe2 crystals can be grown on dielectric substrates using atmospheric chemical vapor deposition in the presence of hydrogen gas. These hexagonal crystals (lateral width >160 um) have a carrier mobility of 100 cm(2) V(-1) s(-1) and a photoresponsivity of ≈1100 mA W(-1), which is comparable to that of exfoliated flakes.

In-plane and out-of-plane arrangements of carbon atoms in graphene layers play critical roles in the fundamental physics and practical applications of these novel two-dimensional materials. Here, we report initial results on the edge/crystal orientations and stacking orders of bi- and tri-layer graphene (BLG and TLG) from Raman spectroscopy and transmission electron microscopy (TEM) experiments...

Laterally large (≈3 µm), atomically thin 2D Bi2O2CO3 nanosheets (2D bismuth oxycarbonate, bismutite) are fabricated via sonochemically assisted, template-free synthesis. Keys to the synthesis of freestanding, laterally from bulk Bi powder choice suspension medium, controlled reaction temperatures, and several hours processing time. Lateral sizes can be between µm-sized tens nm sized nanoflakes ...

A facile fabrication method to produce biocompatible semiconductor Quantum Dots encapsulated in high quality and thick thermal oxide is presented. The process employs sonication of porous Si/SiO2 structures to produce flakes with dimension in the 50-200 nm range. These flakes show a coral-like SiO2 skeleton with Si nanocrystals embedded in and are suitable for functionalization with other diagn...