Wavelength Modulation Spectra and Electronic Band Structure of SnS2 and SnSe2

The first detailed reflectivity and differential reflectivity measurements performed on the layer compounds SnS2 and SnSe2 for energies ranging from 2 to 6 eV are presented. The results are discussed on the basis of existing band structure calculations. The main structures in the optical response of SnS2 and SnSe2 are found to result from excitations from the top most anion p‐type valence states (crystal field split pz and pxy type levels) into the lowest conduction band (anion and cation s‐ and p‐type levels). The location of these structures in k‐space is found to be very close to symmetry determined “special k‐points” for SnS2.