abstract

• We combine linear and nonlinear optical spectroscopy at 4 K with ab initio calculations to study the electronic bandstructure of MoSe2 monolayers. In one-photon photoluminescence excitation (PLE) and reflectivity we measure a separation between the A- and B-exciton emission of 220 meV, in good agreement with our calculations. In two-photon PLE we detect for the A- and B-exciton the 2p state 180 meV above the respective 1s state. In second harmonic generation (SHG) spectroscopy we record an enhancement by more than two orders of magnitude of the SHG signal at resonances of the charged exciton and the 1s and 2p neutral A- and B-exciton. Our post-density functional theory calculations show in the conduction band along the K-Γ direction a local minimum at the Λ-point that is energetically and in k-space close to the global minimum at the K-point. The influence of this local minimum on exciton transitions is discussed. © 2015 IOP Publishing Ltd.

authors

• Amand T.
• Balocchi A.
• Bouet L.
• Gerber I.C.
• Lagarde D.
• Marie X.
• Urbaszek B.
• Vidal Borbolla Miguel Angel
• Wang G.

publication date

• 2015-01-01

funding provided via

• Seventh Framework Programme, FP7: 306719  Grant

published in

• 2D Materials  Journal

keywords

• Excitons; Optical spectroscopy; Transition metal dichalcogenide monolayers Calculations; Density functional theory; Harmonic generation; Monolayers; Nonlinear optics; Photons; Selenium compounds; Semiconductor quantum wells; Transition metals; Ab initio calculations; Electronic band-structure; Inter-band transition; Nonlinear optical spectroscopy; Optical spectroscopy; Photoluminescence excitation; Second harmonic generation spectroscopies; Transition metal dichalcogenides; Excitons

Digital Object Identifier (DOI)

• 10.1088/2053-1583/2/4/045005

start page

end page

volume

• 2

issue

• 4