There are rich physics and chemistry in two-dimensional (2D) layered structures beyond graphene. Using first-principles total energy calculations and in collaboration with experimentalists, we have explored a number of such systems. These include the electron-rich acceptors in Bi2Te3 [1], using native defects as a probe to explore 3D potential profile of Bi2Se3 surfaces [2], and improved CO oxidation under graphene cover. I will further discuss an all-new 2D hafnium honeycomb lattice on metal substrates, with only 2/3 of atomic layer density [3]. Finally, I will show that, by transition metal intercalation, d-band Dirac cone emerges [4] with significantly larger SOC [5]. The TI band gap can be as large as 100 meV, making it possible to carry out room-temperature measurement of Quantum Spin Hall Effect.

References:

[1] Y. Jiang, et al., Nano Letters 13, 2851 (2013).

[2] C. Mann, et al., Nature Comm. 4, 2277 (2013).

[3] L. Li, et al., Nano Letters 13, 4671 (2013).

[4] Y. Li, et al., Phys. Rev. Lett. 109, 206802 (2012).

[5] Y. Li, et al., Phys. Rev. B 87, 245127 (2013).