Tuning the electronic properties of armchair graphene nanoribbons by strain engineering

Atomic and electronic properties of armchair graphene nanoribbons under uni-axial strain are studied by ab initio calculations. Calculations for 5-, 6- and 7-armchair graphene nanoribbons show that at the equilibrium state, the difference in bond lengths in each ribbon is about 0.65 nm. The total energy of AGNRs depends on the strain direction (namely, armchair or zigzag) and is inversely proportional to the nanoribbon width. When the uni-axial strain along armchair or zigzag directions is individually applied, the change in the ribbon band gap can be described as a zigzag pattern with the appearance of the semiconductor-metal-semiconductor phase transition. As a result, deformed AGNRs are becoming a promising material for applications in nanoelectromechanical devices.