Effect of lithium and transition metals embedding on electronic and thermal transport properties of twin graphene

The effective and robust modulation of various properties is crucial for device applications of carbon-based low-dimensional materials. In this work, the embedding of lithium and 3d transition metal (TM) atoms into carbon nanocages of twin graphene, as well as effects on structural, electronic, and lattice thermal transport properties, have been systematically clarified through first-principles calculations and molecular dynamics simulations. The results indicate that the Li, Ti, V, Mn, and Fe-embedded carbon nanocages exhibit energetic stable configurations for the twin graphene, and the evaluated energy barrier for the embedding also implies more dynamic stability compared to surface adsorption. Spin-polarized calculations demonstrate a half-metallic feature in the V-decorated system, while the electronic structure can be further tuned from metallic behavior to semiconductor. Moreover, the lattice thermal conductivity can also be effectively altered by the embedding, and an enhancement/suppression of 38 %/47 % can be achieved at room temperature. Thus, our results indicate great potential for twin graphene-based applications via the utilization of carbon nanocages, and pave new ways to tune various physical properties of low-dimensional carbon networks beyond surface adsorption.