Quantum ATK Analysis and Detection of Toxic Gases Nitrogen Oxide using Pristine, Defective, and Doped Graphene

While doping and defects are often considered detrimental to material performance, at the nanoscale, modifications are needed to create novel properties beneficial for device applications. In this work, we focus on optimizing graphene as a gas sensor for detecting toxic gases such as nitrogen oxide (NO). The study explores the effects of doping graphene sheets with transition metals (Cu, Au, Pt) and introducing a single vacancy (SV) defect at the center of the sheet. Pristine, defected, and doped graphene sheets are systematically analyzed as potential sensing materials for NO gas detection. The investigation includes the design of graphene-based devices and the evaluation of their electrical I-V characteristics under different configurations. The sensing mechanism is examined through parameters such as electronic properties, charge transfer, adsorption energy, electrical characteristics (I-V), sensitivity, and the non-equilibrium Green's function (NEGF) approach. The results indicate that defected graphene demonstrates superior gas adsorption performance, with an adsorption energy of 8.316 eV and a sensitivity of 51.1%, outperforming both pristine and doped graphene. These findings establish defected graphene as a promising candidate for NO gas sensing applications, while doped graphene shows moderate sensing potential.