Influence of Molecular Adsorption on the Electronic Transport Properties of 2D Iodinene with Sensing Potential

Driven by the demand for next-generation gas sensors, this study systematically investigates the impact of molecular adsorption on electronic transport of 2D iodinene-based devices. In equilibrium, adsorption of small molecules has little effect on electron transmission in positive energies but causes suppressed electron transport in negative energies, essentially determined by the relative strength of local electronic rearrangement and adsorption-induced structural relaxation. When in non-equilibrium (the bias exceeds the turn-on voltage of about 1.07 V), Formaldehyde produces the most significant gain of current. At the turn-on voltage, the amplitude of electron transmission is markedly enhanced while the peak position remains stable, indicating that the adsorption amplifies transmission through primary channels and does not introduce adverse level misalignment. In comparison, the enhancement effect on current of methane and CO₂-1 is weaker, displaying 0.04 eV shifts and amplitude gains in electron transmission spectrum at peak biases, indicating partial activation of resonant channels and improved level alignment. Differently, CO₂-2 and especially toluene would attenuate current. Benzene causes minor electronic rearrangement and limited current adjustment. These findings furnish a theoretical foundation for the rational design of highly selective and sensitive gas sensors applicable to environmental monitoring and industrial safety.