2022, Observation of Moiré Excitons in Twisted WS2/WS2 Homostructure Superlattices, Nanoscale

2022, Observation of Moiré Excitons in Twisted WS2/WS2 Homostructure Superlattices, Nanoscale

Abstract:

Moiré superlattices offer a fascinating platform for designing the properties of optical excitons. The moiré pattern can generate an ordered exciton array in space, making it possible for topological excitons and quantum emitters. Recently, evidence of moiré excitons in twisted heterostructures of TMDs has been widely reported. However, to date, the capture and investigation of the moiré excitons in twisted homostructure (T-HS) remains elusive. Here, we report the observation of moiré excitons in WS2/WS2 T-HS with a twist angle of about 1.5°. The PL spectrum of the T-HS region shows many small peaks with nearly constant peak spacing, which is attributed to the reconstructed moiré potential generated by the reconstructed moiré pattern to confine the intralayer excitons, thereby forming an ordered moiré exciton array. Furthermore, we also have studied the influence of different temperatures and laser power on the moiré excitons, as well as the valley polarization of the moiré excitons. Our results provide a promising prospect for further exploration of the artificial excitonic crystals and quantum emitters of TMDs moiré pattern.

Keywords: Moiré superlattices, twisted homostructures, moiré excitons, moiré potential, WS2/WS2

Link:https://pubs.rsc.org/en/content/articlepdf/2022/NR/D2NR02450K

Observation of moiré excitons in the twisted WS2:WS2 homostructure.pdf