A shift of 0. The deposition of subsequent layers of the phthalocyanines has a comparably negligible effect (curves in darker shades of green and lilac). In the more volume-sensitive experiments on the laboratory spectrometer, we obtain the same result for the CoPc/MoS2 heterostructure (Figures and). In contrast, with CoPcF16 (Figures and) no shift to lower binding energy is observed. This indicates that the interaction primarily occurs on the top layer of the molybdenum disulfide. or by the variation of the position of the reference level, the Fermi level. In the present case, the quantitatively identical shift of the positions of the Mo3d and the S2p binding energies, indicate a shift of the substrate Fermi level because of the deposition of molecules, that is, an (interface) doping. Such doping-related core level shifts are well-known: For example, for silicon the Si2p binding energy of heavily n-doped silicon is found at higher values compared to heavily pdoped silicon. These findings fit well to other previous investigations of doping in different heterostructured TMDCs. To gain a deeper understanding of the origin of this doping, we map the band structure obtained by angle-resolved photoelectron spectroscopy (ARPES) in Figure . Figures and display the energy dispersion diagrams for freshly cleaved MoS2, while Figures and depict the diagrams after deposition of monolayers (0.34 nm) of CoPc and CoPcF16, respectively. All energy dispersion diagrams were extracted from cuts through the momentum maps shown in Figures and and the paths are indicated by the red lines. We omit the dispersion diagrams for the thicker films here, as the method is highly surface-sensitive, and substrate-related features are no longer visible, which makes tracing a comparable momentum cut not reliable. To further illustrate changes upon deposition, Figures and represent the integration over the imaged area of the detector for all spectra. The intensity is normalized to facilitate a comparison. The valence band maxima (VBM) at the Γ point for the two freshly cleaved substrates were found at 0.92 and 0.77 eV (Figures and), indicating slight n-type doping, when considering a band gap of 1.23 eV. We note that even in-situ cleaved samples can exhibit a slightly different position of the Fermi level, depending crucially on the number of step edges and other defects in the analyzed area. However, the careful monitoring of the measurement spot (diameter 0.1 mm) on the sample enables the analysis of the same sample region before and after the deposition of the molecules. For CoPc deposition, we observe a positive shift (+ 0.21 eV) of the Γ point to 1.13 eV, while for CoPcF16 deposition, the Γ point moves (-0.11 eV) to 0.66 eV. The direction of these shifts is consistent with the results obtained from XPS core-level measurements, but it is worth noting that the magnitude of these shifts is different. This shows that rigid shifts in the measured core-level provide a qualitative indication of changes in the Fermi level's position. However, for a more precise analysis, the valence band region must be examined.