Figure 3

(a–c) Comparison of Mo 3d, S 2p, and valence-band photoemission spectra obtained by in-situ He⁺ ion irradiation on the freshly cleaved surface of the MoS₂ single crystal. These spectra were taken at the photon energies of hν = 300 eV, 222 eV, and 56 eV, respectively. The red arrows beside the prominent p-type peaks indicate the n-type features (see the context for details). (d) The binding energy shifts of the prominent Mo 3d_5/2 and S 2p_3/2 peaks and the VBM. The binding energies of the cleaved MoS₂ surface are 228.92 eV, 161.74 eV, and 0.30 eV, respectively. (f) Comparison of Lorentzian linewidth of Mo 3d and S 2p core-level spectra. (g) The intensity ratio of the S 2p to Mo 3d core-level spectra.