Unveiling Giant Polarisation Ratio of Chiral Photoluminescence in MoS2 Nanorolligami Fabricated by Centre-to-Edge Rolling Mechanism

Abstract

We introduced mechanical strain to systematically roll monolayer (1-L) MoS₂ into nanostructures with diameters ranging from 100 – 200 nm. The rolled MoS₂ regions exhibit unique anisotropic optical behaviour compared to the flat regions (thickness ≤ 1 nm), as analysed through polarisation-resolved photoluminescence (PL) and Raman spectroscopy. Raman spectroscopy revealed that the E_2g/A_1g intensity ratio under circular polarisation was approximately 0.25 in the rolled regions, whereas it approached zero in the flat region. These findings highlight pronounced optical anisotropy and symmetry-breaking in rolled MoS₂, distinguishing it from the isotropic flat regions. Additionally, angular-dependent PL measurements demonstrated a strongly enhanced linear polarisation ratio (LPR) of 28% and circular polarisation ratio (CPR) of 37% in the rolled regions, indicating strong optical anisotropy. In contrast, the flat MoS₂ regions exhibited isotropic behaviour, with LPR and CPR values typically around 8%. Our results demonstrate that rolling-induced localised deformation profoundly modifies exciton polarisation behaviour in MoS₂. Enabling precise light filtering and nanoscale manipulation via nanoscrolling of the two-dimensional materials, our work lays the foundation for next-generation optoelectronic devices with tailored optical responses and enhanced functionality.