Self-strained MoS₂ growth on optical fiber: exotic excitonic features

Abstract The combination of two-dimensional (2D) materials with optical fibers (OFs) has enriched potential for advancing optical technologies. The distinctive optical and electronic properties of 2D materials such as molybdenum disulfide, along with the flexibility and efficiency of OFs, could lead to novel features such as efficient and electrically tailored optical signal transmission. This study reports monolayer MoS 2 growth on OF and silicon oxide (SiO 2 ) substrates using atmospheric pressure chemical vapor deposition. The optical and structural properties of MoS 2 on both OF and SiO 2 surfaces are compared. Raman spectroscopy reveals uniform monolayer formation across both substrates. However, the photoluminescence spectra demonstrate distinct excitonic behaviors. MoS 2 grown on OF demonstrates a redshift of the A exciton of 30 meV compared to its counterpart on SiO 2 , while the B exciton exhibits significantly higher intensity relative to the A exciton. The B excitons in the OF are also redshifted by 40 meV compared to B excitons in the MoS 2 grown on a SiO 2 /Si substrate. This variation in exciton dynamics is due to the strain effect (biaxial strain) caused by the fiber’s curved geometry, which influences the electronic band structure of MoS 2 . Furthermore, systematic testing of samples at various laser powers confirms the robustness of the MoS 2 layers grown on OFs in different experiments. Our findings highlight the importance of MoS 2 on OF for the upcoming generation of optical devices, especially in communication and quantum optics, emphasizing the role of substrate geometry in tailoring 2D material properties.