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TT: Fachverband Tiefe Temperaturen
TT 33: Nanotubes and Nanoribbons
TT 33.1: Talk
Tuesday, March 13, 2018, 09:30–09:45, H 0110
Excitons in MoS2 nanoribbons: width and localization effects. — •Pino D’Amico1, Deborah Prezzi1, Andrea Ferretti1, and Elisa Molinari2,1 — 1CNR-NANO-S3, Via Campi 213/a I-41125 Modena, Italy — 2Physics, Computer Science and Mathematics Departement, University of Modena and Reggio Emilia, Via Campi 213/a I-41125 Modena, Italy
The formation of 1D wires of carriers at the edges of MoS2 nanoribbons (NRs) represents a case study for spontaneous polarization effects. The spatial confinement and the charge accumulation at the edges make MoS2-NRs a perfect candidate to investigate interaction effects at the nanoscale, also in view of possible applications in solar-energy devices [1,2]. While the electronic and optical properties of MoS2 bulk monolayers have been the focus of an intense research, the investigation of MoS2-NRs is at the early stages. We will present a first principle investigation of the electronic structure and optical absorption of MoS2-NRs as a function of the NR width, as obtained within the framework of many-body perturbation theory, according to the G0W0 plus Bethe-Salpeter-Equation scheme. We will show that both width-dependent and width-independent mechanisms emerges in the formation of excitonic excitations, and we will explain the relationship between those two mechanisms and the edge-localization of the carriers. Since the investigated MoS2-NRs are metallic, the present work deals with the fundamental issue of the presence of excitons in metals[3].
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