Substrate effects on 2D defects published in Phys. Rev. Mater.


D. Wang and R. Sundararaman, “Substrate effects on charged defects in two-dimensional materials”, Phys. Rev. Mater. 3, 083803 (2019) (Preprint: arXiv:1908.05208)

Capturing the surrounding dielectric effects (including substrate) on charged defects in two-dimensional (2D) materials is very important for fundamental physics and technological applications, but remains challenging due to extremely high computational cost. In this paper, we present a general continuum model approach to incorporate substrate effects directly in density-functional theory calculations of charged defects in the 2D material alone. Results obtained by this method agree very well with explicit calculations that directly include substrate atoms, but at a small fraction of the computational effort. Applications to defects in MoS2 and hBN with SiO2 and diamond substrates reveal that the increased screening stabilizes the charged defects and thus lowers the defect ionization energy. This method establishes a foundation for high-throughput computational screening of new quantum defects in 2D materials that critically accounts for substrate effects.