Angle-Resolved Polarized Raman Spectra of Linear MoS₂ Nanostructures for Optical Anisotropy Detection

Abstract

The linear molybdenum disulfide (MoS 2 ) with different nanostructures due to atomic arrangements is expected to show promising prospects in the next generation electronics and optoelectronic devices. In this work, three typical linear MoS 2 nanostructures were grown on the SiO 2 / Si (285 nm, 500 μm) substrate by a modified chemical vapor deposition (CVD) method and were systematically analyzed by using angle-resolved polarized (ARP) Raman spectra. The results are as follows. The first and the second linear MoS 2 are identified as nanoribbon-like structures with a tiled layered arrangement similar with the sheet MoS 2 , where the first linear MoS 2 is grown directly on the substrate and the second linear MoS 2 is coated on the upper surface of the cylindrical-shaped molybdenum oxide (MoO 3 ). The third linear MoS 2 is a nanotube-like structure, and its atomic structure includes vertical layered arrangement in addition. All three linear MoS 2 produce a small-size effect, and the second linear MoS 2 is more like an intermediate material between the first linear MoS 2 and the third linear MoS 2 during the growth of CVD. This study provides an effective approach to detect the optical anisotropy of linear nanostructures of two-dimensional materials which has potential applications in ARP optoelectronics devices.