Engineering of Neutral Excitons and Exciton Complexes in Transition Metal Dichalcogenide Monolayers through External Dielectric Screening
| Autor: | Borghardt, Sven, Tu, Jhih-Sian, Winkler, Florian, Schubert, Jürgen, Zander, Willi, Lesson, Kristján, Kardynał, Beata E. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Phys. Rev. Materials 1, 054001 (2017) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevMaterials.1.054001 |
| Popis: | In order to fully exploit the potential of transition metal dichalcogenide monolayers (TMD-MLs), the well-controlled creation of atomically sharp lateral heterojunctions within these materials is highly desirable. A promising approach to create such heterojunctions is the local modulation of the electronic structure of an intrinsic TMD-ML via dielectric screening induced by its surrounding materials. For the realization of this non-invasive approach, an in-depth understanding of such dielectric effects is required. We report on the modulations of excitonic transitions in TMD-MLs through the effect of dielectric environments including low-k and high-k dielectric materials. We present absolute tuning ranges as large as 37 meV for the optical band gaps of WSe 2 and MoSe 2 MLs and relative tuning ranges on the order of 30% for the binding energies of neutral excitons in WSe 2 MLs. The findings suggest the possibility to reduce the electronic band gap of WSe 2 MLs by 120 meV, paving the way towards dielectrically defined lateral heterojunctions. Comment: 11 pages + 6 pages supporting information |
| Databáze: | arXiv |
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