Molecular charge transfer by adsorbing TCNQ/TTF molecules via π-π interaction: a simple and effective strategy to modulate the electronic and magnetic behaviors of zigzag SiC nanoribbons.

By means of first-principles computations, we first propose a simple and effective strategy through the molecular charge transfer via noncovalent π-π interaction to modulate the electronic and magnetic properties of zigzag SiC nanoribbons (zSiCNRs). This charge transfer is induced by adsorbing the electron-withdrawing/donating tetracyanoquinodimethane (TCNQ) or tetrathiafulvalene (TTF) molecules on the surface of the pristine zSiCNR. It is revealed that all the TCNQ- and TTF-modified zSiCNR-systems can exhibit considerable adsorption energies in the range from -137.2 to -184.0 kJ mol(-1) and from -71.3 to -76.9 kJ mol(-1), respectively, indicating that these zSiCNR-complexes possess high structure stabilities. This kind of a molecular charge transfer via π-π interaction can break the magnetic degeneracy of zSiCNRs, and the sole ferromagnetic (FM) metallicity and even antiferromagnetic (AFM) half-metallicity can be achieved. These intriguing findings will be advantageous for promoting SiC-based nanomaterials in the application of spintronics and multifunctional nanodevices in the near future.