Residual Molecular Groups’ Adsorption in Tuning the Transport Properties of Carbon Nanotubes

Carbon nanotubes (CNTs) have attracted much attention due to their unique electronic structures and transport properties for the application of carbon-based sensor components. It is doubtful in experiments that if the adsorbates, such as the groups of conjugated polymers, hinder the performance of transport on CNTs. Here, we systemically studied the transport properties of common groups (−CH₃, −C₆H₅, −NH₂, −OH) adsorbed on (7, 0)-CNT by first-principles calculations. Our results show that the adsorption of surface groups will lead to different impurity states near the Fermi level. The localized electrons at the Fermi level limit the electrical transport properties of CNTs. The electron transport capacity of CNTs becomes weaker with increase in the impurity concentration and the carrier mobility becomes lower. Our research provides an instructive theoretical foundation for fabricating high-performance carbon-based sensor devices.