First-principle investigations of Cl decorated armchair GaN nanoribbons

The effect of Cl functionalization on the electronic properties of armchair GaN (AGaN) nanoribbons in five different configurations has been investigated by employing density functional theory (DFT) based first-principle calculations. We investigate the structural stability of AGaN nanoribbons through adsorption energy calculation which revealed that Cl functionalization at Ga edge while other edge is H passivated (Cl-AGaN-H) results in the most stable ground state. The bonding of Cl with edge Ga/N atoms takes place via formation of stable chemical bonds and the calculated adsorption energy varies from −1.76 to −4.80 eV for ribbon width Na=9. All the structures settled in non-magnetic ground state and are predicted to be immune against thermal excitations. Interestingly, a transition from direct to indirect band gap has been observed in the selective structures of Cl functionalized AGaN. The increment of observed band gap while decreasing the ribbon width is further confirmation of prevailing quantum confinement effects. Our findings include that Cl-functionalization could be a viable way to tailor the electronic band gap of AGaN for futuristic device applications.