Search results

14 records were found.

We present a theory of current conduction through buckyball(C60) molecules on silicon by coupling a density functional treatment of the molecular levels embedded in silicon with a non-equilibrium Green's function (NEGF) treatment of quantum transport. Several experimental variations in conductance-voltage(G-V) characteristics are quantitatively accounted for by varying the detailed molecule-silicon bonding geometries. We identify how variations in contact surface microstructure influence the number, positions and shapes of the conductance peaks, while varying separations of the scanning probe from the molecules influence their peak amplitudes.
A real-space quantum transport simulator for carbon nanoribbon (CNR) MOSFETs has been developed. Using this simulator, the performance of carbon nanoribbon (CNR) MOSFETs is examined in the ballistic limit. The impact of quantum effects on device performance of CNR MOSFETs is also studied. We found that 2D semi-infinite graphene contacts provide metal-induced-gap-states (MIGS) in the CNR channel. These states would provide quantum tunneling in the short channel device and cause Fermi level pining. These effects cause device performance degradation both on the ON-state and the OFF-state. Pure 1D devices (infinite contacts), however, show no MIGS. Quantum tunneling effects are still playing an important role in the device characteristics. Conduction due to band-to-band tunneling is accurately captured in our simulations. It is important...
Comment: to be published in Phys. Rev. B 69, No.3, 0353XX (2004)
We ana/lyze the performance of a recently reported Ge/Si core/shell nanowire transistor using a semiclassical, ballistic transport model and an sp3d5s* tight-binding treatment of the electronic structure. Comparison of the measured performance of the device with the effects of series resistance removed to the simulated result assuming ballistic transport shows that the experimental device operates between 60 and 85% of the ballistic limit. For this !15 nm diameter Ge nanowire, we also find that 14−18 modes are occupied at room temperature under ON-current conditions with ION/IOFF ) 100. To observe true one-dimensional transport in a 〈110〉Ge nanowire transistor, the nanowire diameter would have to be less than about 5 nm. The methodology described here should prove useful for analyzing and comparing on a common basis nanowire transistor...
Want to know more?If you want to know more about this cutting edge product, or schedule a demonstration on your own organisation, please feel free to contact us or read the available documentation at