Atomic orbitals and photoelectron intensity angular distribution patterns of MoS2 valence band

The ratio of atomic orbitals contributing to the valence band can be determined from the photoelectron intensity angular distribution (PIAD) by using linearly polarized light and display-type spherical mirror analyzer. The experiment was done for MoS2 using a linearly polarized light at the photon energy of 45 eV perpendicularly incident to the sample surface. Atomic orbitals contributing to the bands near the Fermi level were investigated. The PIAD patterns around the image point showed splitting of intensity. The intensity at the top and bottom image points was strong, while the intensity was weak at the left and right side K points. The PIAD patterns from various kinds of atomic orbitals were calculated. By comparing the experimental PIAD patterns to the simulated ones, we concluded that at the image point Mo 4dz2 and S 3pz atomic orbitals are the main components and at the K points the Mo 4dxy atomic orbital is dominant. The atomic orbital Mo 4dx2−y2 also gives contribution to the PIAD pattern. These results were in good agreement with the coefficients of the atomic orbitals derived using ab initio band calculation.