| AVS 63rd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Thursday Sessions |
| Session 2D+MI-ThM |
| Session: | Properties of 2D Materials including Electronic, Magnetic, Optical, Mechanical, Thermal Properties |
| Presenter: | Joseph Gonzales, University of South Florida |
| Authors: | I.I. Oleynik, University of South Florida J.M. Gonzales, University of South Florida |
| Correspondent: | Click to Email |
The optical excitations in semiconductors are substantially influenced by electron-hole interactions resulting in formation of excitons. Although the exciton binding energies in the bulk are much smaller that the fundamental band gaps, the excitonic effects in 2D materials are significantly amplified due to combined effect of quantum confinement and non-local screening of electron-hole interactions in two dimensions. An effective mass theory of 2D excitons, which takes into account the combined effect of the anisotropy and non-local 2D screening, is used to systematically investigate the variation of monolayer exciton binding energies Ex across a representative set of layered chalcogenides, both isotropic, such as MoTe2, MoSe2, WSe2, and WS2, and anisotropic including phosphorene, TiS3, ReS2, and SnSe2. The markedly different values of Ex are correlated with corresponding variations in atomic polarizabilities of constituent atoms.