Probing the Interlayer Exciton Physics in a MoS2/MoSe2/MoS2 van der Waals Heterostructure

• DOI: 10.1021/acs.nanolett.7b03184
• Publication Date: 2017-09-12T15:21:05Z
• Authors: M. Baranowski; A. Surrente; L. Klopotowski; J. M. Urban; N. Zhang; D. K. Maude; K. Wiwatowski; S. Mackowski; Y. C. Kung; D. Dumcenco; A. Kis; P. Plochocka
• Keywords: Transition metal dichalcogenides, van der Waals heterostructures, interlayer exciton, chemical vapor deposition, valley polarization; Condensed Matter - Mesoscale and Nanoscale Physics; transition metal dichalcogenides; FOS: Physical sciences; 02 engineering and technology; 530; 01 natural sciences; Transition metal dichalcogenides; chemical vapor deposition; 0104 chemical sciences; [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con]; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); van der Waals heterostructures; interlayer exciton; valley polarization; 0210 nano-technology

Stacking atomic monolayers of semiconducting transition metal dichalcogenides (TMDs) has emerged as an effective way to engineer their properties. In principle, the staggered band alignment TMD heterostructures should result in formation interlayer excitons with long lifetimes and robust valley polarization. However, these features have been observed simultaneously only MoSe2/WSe2 heterostructures. Here we report on observation long-lived exciton emission a MoS2/MoSe2/MoS2 trilayer van der Waals heterostructure. The nature is confirmed by photoluminescence spectroscopy, well analyzing temporal, excitation power, temperature dependence peak. complex dynamics suggests presence quasi-degenerate momentum-direct momentum-indirect bandgaps. We show that circularly polarized optical pumping results polarization exciton. Intriguingly, helicity opposite excitation. Our through careful choice TMDs forming heterostructure it possible control circular emission.