Optical properties of armchair graphene nanoribbons under uniaxial strain

The optical properties of armchair graphene nanoribbons (AGNRs) under the uniaxial strain are studied within a non-orthogonal tight-binding model. For 9-AGNR and 10-AGNR, the first transition energy E11 increases and the second one E22 decreases when the uniaxial strain increases. And for 10-AGNR, there is a crossover for the two transition energies under the uniaxial strain. While for 11-AGNR, the E11 transition energy decreases firstly and then increases and the E22 transition energy increases when the uniaxial strain increases. Interestingly, there is a semiconductor–metal transition for 11-AGNR with increasing strain. These variations of the optical transition energies can be used as a supplemented tool to detect the deformation degree of an AGNR under the uniaxial strain.