Simulation of the formation for molecular compounds of nanotubes with different chirality indexes to create new molecular devices on their basis

Abstract

The main property of carbon nanotubes that determinates their wide application in electronics is a change of the chirality for ideal structure of a nanotube at implementing of structural Stone-Wales defect (pentagon-heptagon pairs) to its atomic framework. This property allows us to create nanotube-based different electronic devices (diodes, transistors, resistors), similar to traditional silicon devices. Nanotube with incorporated defect can be considered as a metalsemiconductor heterojunction. On the basis of this heterojunction semiconductor elements of very small size can be implemented, less than the current silicon elements. To create devices based on metal-semiconductor heterojunction is necessary to know the mechanisms of formation of the molecular compounds of nanotubes with different chirality. The aim of this work is a theoretical study of the formation of the molecular compounds of nanotubes with different chirality leading to the appearance of the metal-semiconductor heterojunction using molecular modeling methods. The object of investigation is a heterojunction formed by the compound of nanotubes with chirality indices (13,10) and (14, 10). To identify regularities of change in the electronic structure of the compound nanotubes we calculated the density of electronic states (DOS) for the heterojunction, and for each of its constituent chiral tubes. Also, we carried out a numerical evaluation of the reaction enthalpy of formation of the heterojunction. Based on these results it can be concluded that the investigated molecular compounds can be used to create highly sensitive sensors.