Abstract: Calculations have been made for the electronic structures of (10,0) single-walled carbon nanotube containing nitrogen impurity atoms by means of abinitiodensity functional theory. When carbon atom of carbonnanotube is substituted by nitrogen atom, the carbon nanotube will be turned into n-type semiconductor. However, when nitrogen atom is absorbed on the outer surface of the carbon nanotube, it will be transformed into p-type semiconductor. And a portion of electrons inp orbital at the carbon atom adjacent to nitrogen is excited into d orbital. 

Key words: carbon nanotube, nitrogen, doping, electronic structure