Enhanced excitonic features in an anisotropic ReS2/WSe2 heterostructure

Arslan Usman, M. Adel Aly, Hilary Masenda, Joshua J. P. Thompson, Surani M. Gunasekera, Marcin Mucha-Kruczynski, Samuel Brem, Ermin Malic, Martin Koch

Research output: Contribution to journalArticlepeer-review

7 Citations (SciVal)

Abstract

Two-dimensional (2D) semiconductors have opened new horizons for future optoelectronic applications through efficient light–matter and many-body interactions at quantum level. Anisotropic 2D materials like rhenium disulphide (ReS2) present a new class of materials with polarized excitonic resonances. Here, we demonstrate a WSe2/ReS2 heterostructure which exhibits a significant photoluminescence quenching at room temperature as well as at low temperatures. This indicates an efficient charge transfer due to the electron–hole exchange interaction. The band alignment of two materials suggests that electrons optically injected into WSe2 are transferred to ReS2. Polarization resolved luminescence measurements reveal two additional polarization-sensitive exciton peaks in ReS2 in addition to the two conventional exciton resonances X1 and X2. Furthermore, for ReS2 we observe two charged excitons (trions) with binding energies of 18 meV and 15 meV, respectively. The bi-excitons of WSe2 become polarization sensitive and inherit polarizing properties from the underlying ReS2 layers, which act as patterned substrates for top layer. Overall, our findings provide a better understanding of optical signatures in 2D anisotropic materials.

Original languageEnglish
Pages (from-to)10851-10861
Number of pages11
JournalNanoscale
Volume14
Issue number30
Early online date15 Jul 2022
DOIs
Publication statusPublished - 14 Aug 2022

Bibliographical note

We acknowledge the group of Prof. Gregor Witte for providing the AFM image (Fig. S2†). In addition, we acknowledge support from the Collaborative Research Center SFB 1083 funded by the Deutsche Forschungsgemeinschaft and the European Union's Horizon 2020 Research and Innovation Program under grant agreement no. 881603 (Graphene Flagship). M. Adel Aly acknowledges support from the Egyptian Ministry of Higher Education and Scientific Research and Deutsche Akademische Austaush Dienst (DAAD). Further we acknowledge the support by the Alexander von Humboldt (AvH) foundation via a research grant in the Georg Förster fellowship program.

ASJC Scopus subject areas

  • Materials Science(all)

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