Abstract
A graphite nanotube is composed of Gemini type hexabenzocoronene (Gemini-HBC) as the hole-transport layer and the fullerene as the electron-transport layer. We study the doping effect on the electronic properties of Gemini-HBC to make the absorption peak broader, expecting to cover an unharvested energy resource. Here we assume that structure of doped Gemini-HBC is well represented by substituting dopant atom to one of carbon sites. Calculations of the energy and absorption spectrum are performed by the ab-initio computational method. As a result, the absorption peak of the Gemini-HBC is about 0.5μm, whereas the first and second peaks for doped Gemini-HBC are also approximately 0.5μm. In addition, the absorption spectrum of F-doped Gemini-HBC has an additional peak around 0.95μm, implying the sunlight with the longer wavelength may be absorbed.
