Delocalized excitons in thin anisotropic crystals

Abstract

Abstract The ordinary absorption spectrum of MoS 2 contains two series of exciton absorption bands associated with direct optical transitions from a split valence band. In thick crystals the first five members of each exciton series have been detected; these exciton bands move to higher energies and show a diminishing diamagnetic shift with decreasing crystal thickness. The exciton series limit in thin crystals is determined from the oscillatory magneto absorption which occurs to the high energy side of the short wavelength series.