Spin polarized transport in semiconductors – Challenges for Nanolithography

Graphene, even with excellent transport properties, still have serious drawbacks for practical applications. In particular, its gapless character makes it difficult to turn off the current in graphene transistors and leads to a poor saturation of current. Many efforts of bandgap engineering have been made to overcome these limitations. For instance, they consist in cutting 2D graphene sheets into 1D nanoribbons [1], Bernal-stacking of graphene on hexagonal boron-nitride substrate [2], nitrogen-doped graphene [3], creating graphene nanohole lattice [4], and Bernal-stacking bilayer graphene [5]. However, each of these techniques still has its own issues.