No abstract

Atomic configurations of individual single-walled and double-walled carbon nanotubes have been obtained by high-resolution transmission electron microscopy with atomic sensitivity. A structural reconstruction is carried out by Fourier-filtered analysis of Moiré patterns, and it is now possible to acquire the carbon honeycomb lattice images through all of the periphery of individual nanotubes. This visualization technique provides supplementary access in nanoscale characterizations by combining with scanning tunneling microscopy.

A new thermal to electric conversion scheme based on an excitation transfer and tunneling mechanism is studied theoretically. Coulomb coupling dominates when the hot side and the cold side are very close. Two important concepts went into the device scheme: (1) Coulomb coupling, to try to increase throughput power (which is not subject to blackbody limit), and (2) a quantum dot implementation, to restrict number of states, to try to increase efficiency. Modeling efforts from Bloch equations, brute force numerical simulations, and the secular equations partitioning method are discussed. A hot-side quantum dot design of the device is considered. Alternative implementation where the hot-side is a plain sheet of metal or aluminum oxide is analyzed. We found that the model power/area is higher than the blackbody limit, and the predicted conversion efficiency is very high.