2014/02/28 by Changjian Zhang, Haining Wang, Weimin Chan +2
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Absorption (acoustics) #Absorption spectroscopy #Atomic physics #Chalcogenide Semiconductor Thin Films #Condensed matter physics #Exciton #Optics #Pauli exclusion principle #Perovskite Materials and Applications #Physics #Quantum mechanics #Spectral line #Trion #Wave function #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.89.205436
published as Phys. Rev. B 89, 205436 (2014) · 11 pages, 8 figures, some typos in the previous version have been corrected
arxiv created 2014/04/12 · openalex publication_date 2014/05/29 · arxiv updated 2014/06/04 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We measure the optical-absorption spectra and optical conductivities of excitons and trions in monolayers of metal dichalcogenide MoS2 and compare the results with theoretical models. Our results show that the Wannier-Mott model for excitons with modifications to account for small exciton radii and large exciton relative wave function spread in momentum space, phase space blocking due to Pauli exclusion in doped materials, and wave-vector-dependent dielectric constant gives results that agree well with experiments. The measured exciton optical-absorption spectra are used to obtain experimental estimates for the exciton radii that fall in the 7--10\phantom\rule4.pt0ex\text\AA range and agree well with theory. The measured trion optical-absorption spectra are used to obtain values for the trion radii that also agree well with theory. The measured values of the exciton and trion radii correspond to binding energies that are in good agreement with values obtained from first-principles calculations.