Observation of moire excitons in the twisted WS2/WS2 homostructure

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

Automated summary

Moire superlattices provide a platform for designing the properties of optical excitons and enable the exploration of topological excitons and quantum emitters. This study observes moire excitons in the WS2/WS2 T-HS and investigates the effect of temperature and laser power on the excitons.