First-principles study of sensing SO2 adsorption on III-V nitride nanoribbons

The design of efficient, low dimensional sensors is an active topic of research and development. Here, we study the adsorption of SO2 molecules on the edges of III-V nitride nanoribbons to explore their sensing potentials. Zigzag nanoribbons (ZXNNR) and armchair nanoribbons (AXNNR), X = B,Al,Ga, have been investigated. It was noticed that the adsorption of SO2 is mediated via formation of chemical bonds. The calculated adsorption energy varies from -1.09 eV to -4.89 eV for ZXNNR and -0.42 eV to -4.61 eV for AXNNR which ensures the structural stability of considered configurations against thermal excitations. Moreover, for all ZXNNR, a semiconducting to metallic transition has been observed whereas the band gaps in AXNNR are subjected to the adsorption configuration. Further, the selectivity of SO2 with all considered configurations with respect to O-2 and N-2 is also studied. It is revealed that the selectivity of SO2 with respect to N-2 is more suitable as compared to O-2. The analysis of recovery time indicates an excellent reversible characteristics in BN nanoribbons irrespective of their edge geometries. GaN nanoribbons could be reversible only for zigzag edges whereas unusually long recovery time in AIN nanoribbons presents them as a disposable sensing material. Present analysis portrays a detailed comparison of zigzag and armchair III-V nanoribbons towards their potential for designing futuristic nano-sensor devices.