Non-equilibrium first-principles simulations of transition metal dichalcogenide field effect transistors

For the development and optimization of next-generation sub-10 nm field-effect transistors (FETs) based on novel semiconductors such as two-dimensional (2D) transition metal dichalcogenides, non-equilibrium first-principles simulations will be playing an increasingly important role by revealing the atomic-scale details that are not easily accessible in experiments. However, the standard approach combining density functional theory (DFT) and non-equilibrium Green’s function formalism within the Landauer framework has been limited in several aspects in simulating 2D FETs under finite-bias conditions. In this presentation, utilizing the multi-space constrained-search density functional theory (MS-DFT) [1-3] formalism our group has developed, we analyze the non-equilibrium electronic structure and quantum transport properties of TMDC FETs as a function of the gate voltage (transfer characteristics) and drain voltage (output characteristics). We will particularly address the impact of metal types and metal-TMDC contact configurations on FET characteristics, and additionally explore the electrostatic embedding approach to accelerate MS-DFT calculations by including the dielectric environmental effect using the quantum mechanics/continuum multiscale approach.

[1] J. Lee et al. Proc. Natl. Acad. Sci. U.S.A., 117, 10142 (2020)

[2] J. Lee et al. Adv. Sci., 7, 2001038 (2020)

[3] T.H. Kim et al. Npj Comput. Mater. 8, 50 (2022)