Desorption of Adsorbed Gas Molecule on a Pentagon at a Tip of Carbon Nanotube by Pulse Laser Irradiation

Six pentagons located at a tip of MWNT and behavior of a single gas molecule on the pentagons can be observed by field emission microscopy (FEM) using multiwall carbon nanotube (MWNT) with clean surface. Pulse laser irradiation is effective method to obtain the clean surface, and desorption of molecule on a pentagon can be artificially and responsively controlled by this method. Adsorption of a gas molecule onto a pentagon brings about a change from a pentagonal ring image to a bright circular spot image with stepwise increase of V emission current, and vice versa. This switching action of emission current corresponding to adsorption and desorption of a single molecule with a good reproducibility makes to expect an application to monomolecular devices