title: Observation of Excitonic Rydberg States in Monolayer MoS2 and WS2 by Photoluminescence Excitation Spectroscopy.
abstract: We have identified excited exciton states in monolayers of MoS2 and WS2 supported on fused silica by means of photoluminescence excitation spectroscopy. In monolayer WS2, the positions of the excited A exciton states imply an exciton binding energy of 0.32 eV. In monolayer MoS2, excited exciton transitions are observed at energies of 2.24 and 2.34 eV. Assigning these states to the B exciton Rydberg series yields an exciton binding energy of 0.44 eV.
authors: Heather M
authors: HM
authors: Hill
authors: Albert F
authors: AF
authors: Rigosi
authors: Cyrielle
authors: C
authors: Roquelet
authors: Alexey
authors: A
authors: Chernikov
authors: Timothy C
authors: TC
authors: Berkelbach
authors: David R
authors: DR
authors: Reichman
authors: §Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States.
authors: Mark S
authors: MS
authors: Hybertsen
authors: Louis E
authors: LE
authors: Brus
authors: Tony F
authors: TF
authors: Heinz
mesh_terms: D004220:Disulfides / Q000737:chemistry*; D049449:Luminescence; D008982:Molybdenum / Q000737:chemistry*; D036103:Nanotechnology; D012666:Semiconductors; D013057:Spectrum Analysis; D017973:Tungsten Compounds / Q000737:chemistry*
chemical_list: D004220:Disulfides; D017973:Tungsten Compounds; D008982:Molybdenum
keywords: 2D materials; Transition metal dichalcogenides; binding energy; excitons; molybdenum disulfide; tungsten disulfide