• 文献标题:   Density functionals combined with van der Waals corrections for graphene adsorbed on layered materials
  • 文献类型:   Article
  • 作  者:   TANG H, CHOWDHURY STUR, TAO JM, PERDEW JP
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Temple Univ
  • 被引频次:   0
  • DOI:   10.1103/PhysRevB.101.195426
  • 出版年:   2020

▎ 摘  要

Standard density functionals like Perdew-Burke-Ernzerhof (PBE) or Strongly Constrained and Appropriately Normed (SCAN) need a correction to account for long-range van der Waals (vdW) interaction. The damped Zaremba-Kohn model (dZK) [J. Tao, H. Tang, A. Patra, P. Bhattarai, and J. P. Perdew, Phys. Rev. B 97, 165403 (2018)] starts from a formula for the vdW interaction of a distant atom with a solid surface, both with known dielectric properties, damps this formula at short range, and then treats an adsorbed molecule or atomic layer as a collection of renormalized atoms. We extend this model to graphene adsorbed on semiconducting layered materials [bulk graphite and hBN, and multilayer transition metal dichalcogenides (TMD)] by including the C-4 asymptotic term and multiple electrostatic image effects due to the two surfaces of the substrate slabs in the vdW calculations. The resulting SCAN-vdW-dZK and PBE-vdW-dZK give approximately the same results for the systems considered here, in agreement with available reference values. The predicted binding energies are roughly 25% lower than those from SCAN-rVV10 (revised Vydrov and Van Voorhis 2010), and similar to 15% lower than those from PBE-rVV10. Since SCAN-rVV10 usually overbinds, the predicted binding energies by SCAN-vdW-dZK and PBE-vdW-dZK are expected to be closer to the true values. The predicted equilibrium binding distances from SCAN-vdW-dZK and PBE-vdW-dZK are slightly larger (similar to 0.1 angstrom) than those from SCAN-rVV10, and close to those from SCAN. The binding energy depends upon the number of substrate layers more strongly in vdW-dZK than in rVV10. The C-4-term contributions can be 40% of the total vdW interactions, and the C-5 term contributes about 10%. The effects of images and the back surfaces of slabs can contribute about 4-10%. The vdW interaction energy power laws from the vdW-dZK model for graphene adsorbed on multilayer MoS2 show slowly varying decay to the pairwise exponent -4 with increasing separation D, very similar to those obtained from the random-phase approximation and renormalization group approaches by Ambrosetti et al. Both the PBE-vdW-dZK and SCAN-vdW-dZK give a greater increase in interlayer binding energy when the TMD substrate changes from monolayer to four-layer for the graphene/TMD adsorption systems. This is consistent with the relevant electron-energy-loss spectroscopy experimental results showing increased dielectric response from the substrate with increasing substrate layer number.