Predicting Selective Sensing Capability of Armchair Graphene Nanoribbon toward Hydrogen Halide Gases: A Density-of-State Analysis

Nonequilibrium Green’s function formalism is used to set the chemiresistor device for analyzing the sensing ability of pristine and metal-doped (Al, Fe and Mn) armchair graphene nanoribbons (AGNRs) for the detection of hydrogen halide gases — HF, HCl and HBr. Metal doping is found to enhance the adsorptive strength and sensing ability of the ribbon. On Al-AGNR, all three halide gases follow dissociative chemisorption while on Fe-AGNR and Mn-AGNR, these gases adsorb nondissociatively. The computed current–voltage characteristics indicate selective response of Mn-AGNR toward HF and of Fe-AGNR toward HBr. The origin of this selectivity has been discussed in terms of difference in the density-of-state profiles of the studied AGNR systems.