Fig. 1: Two-level quantum defect screening in WS2.
a Two defect configurations that are considered in this work: substitution on the W site (MW, red) is shown on the left and on S site (MS, red) is depicted on the right. W atoms are colored green and S atoms are displayed in yellow. b Transition dipole moment vs. single-particle excitation energy at the single-shot PBE0. The marker and color scheme stand for the defect structure and whether the ground state is singlet or not. Each point stands for a charge defect that is thermodynamically stable within a certain Fermi level (EF) range in the band gap, and with electronic structures that possess two localized defect levels within the band gap, as shown in the inset. Below the conduction band (CB, light green) and above the valence band (VB, light blue), a filled state (orange arrow) to empty state (white arrow) transition is shown.
