  In this article, we report band structure studies of zigzag graphene
nanoribbons (ZGNRs) on introducing defects (sp_3 hybridized carbon atoms) in
different concentrations at edges by varying the ratio of sp_3 to sp_2
hybridized carbon atoms. On the basis of theoretical analyses, band gap values
of ZGNRs are found to be strongly dependent on relative arrangement of sp3 to
sp2 hybridized carbon atoms at the edges for a defect concentration; so the
findings would greatly help in understanding band gap of nanoribbons for their
electronic applications.
