Engineering energy gap of the carbon saturated nanowire and investigating the ammonia molecule doping effects by using the initial calculations (Ab initio)

In this paper size effects, growth orientation and also doping by Ammonia molecule (NH3) on the carbon nanowire properties with saturated diamond structure by (DNw:H) have been investigated. This study was carried out using DFT theory and Kohn-Sham equation by self-consistent field (SCF) that performed by local density approximation (LDA). The nanowires morphology is cylindrical with [111] growth orientation and their lateral surface was saturated by hydrogen atoms. The results show that band gap of these nanowires is smaller to bulk diamond due to high surface to volume ratio and formation surface level. The results of ammonia molecule doping with carbon surface atoms at saturated diamond nanowire in [100] orientation lead to decrease in band gap until nanowire converted into a n-type semiconductor.