In the present work, Raman and photoluminescence spectroscopies were used to study the dynamics of phonons and different excitons of MoS2 bilayer under a rotation of 29∘ dependent of the temperature. The twisted bilayer (T-2L) of MoS2 was obtained through mechanical exfoliation, and subsequently rotated using a dimethyl polysiloxane (PDMS) substrate and deterministic transferred to a SiO2 substrate. The Raman spectrum of the twisted bilayer presents three peaks E′ (386 cm−1), A1′ (405 cm−1) and an FA′ peak at approximately 409 cm−1 linked to the A1′ mode, which is attributed to a Moir\'e pattern phonon. Both modes (A1′ and FA′) are dependent of light polarization in a way that demonstrates an effective coupling between the layers. It was also verified through the Gr\"uneisen parameter, an increase in the anharmonicity of the mode in the E′ plane and a decrease the same for A1′. In the PL measurements, the appearance of an exciton in T-2L was verified, which generated a second shoulder measured at ≈1.58 eV attributed to an indirect transition of an I trion. The interaction between the rotated monolayers of MoS2 proved to be an important parameter for possible fine-tuning of the properties of bilayer samples.
@article{arxiv.2402.03272,
title = {Phonon and exciton temperature-dependent properties of twisted MoS$_2$},
author = {Francisco Silva-Santos and Ruben da Silva and Yuset Guerra Dávila and Maykol Oliveira and Zhuohang Yu and Mauricio Terrones and Antonio Souza Filho and Rafael Alencar and Bartolomeu Viana},
journal= {arXiv preprint arXiv:2402.03272},
year = {2024}
}