Fig. 3: DFT calculations.
From: Spatial defects nanoengineering for bipolar conductivity in MoS2
Atom normalized spin-polarized projected density of states (PDOS) of MoS2 with one S vacancy and one (Sv–1Sd) (a), two (Sv–2Sd) (b), and three (Sv–3Sd) (c) protruding surface S atoms chemisorbed on the surface. The energy level of the valence band maximum (VBMDFT) is calculated with respect to the vacuum level, and it is indicated by a blue dashed line, while the VBM of pristine MoS2 is shown with a black dashed line and obtained from Ref 37. d The schematic figures of the corresponding MoS2 structures used in PDOS calculations. The S atom (S1) underneath a S vacancy, the regular S atom (S2), and the protruding S atom (S3) covalently bonded to a S atom on the surface (S4) are colored in orange, yellow, green, and blue, respectively. Mo atoms are represented by violet balls. e The core-level energy shifts of S 2p states with respect to regular S atom (S2) (0.00 eV) are indicated. f Histogram of the DFT results (in dark blue and dark green) for the bottom (S4) and protruding S (S3) atoms with creation of a S vacancy together with the XPS energy shifts (in light green and light blue) of the two additional doublets used for the fit.
