Magnetic Field Alignment and Optical Anisotropy of MoS2 Nanosheets Dispersed in a Liquid Crystal Polymer

• Published in: The journal of physical chemistry letters Vol. 13; no. 34; pp. 7994 - 8001
• Main Authors: Gabinet, Uri R., Lee, Changyeon, Kim, Na Kyung, Hulman, Martin, Thompson, Sarah M., Kagan, Cherie R., Osuji, Chinedum O.
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01-09-2022
• Subjects: Physical Insights into Materials and Molecular Properties
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.2c01819

Molybdenum disulfide (MoS2) nanosheets exhibit anisotropic optical and electronic properties, stemming from their shape and electronic structure. Unveiling this anisotropy for study and usage in materials and devices requires the ability to control the orientation of dispersed nanosheets, but to date this has proved a challenging proposition. Here, we demonstrate magnetic field driven alignment of MoS2 nanosheets in a liquid crystal (LC) polymer and unveil the optical properties of the resulting anisotropic assembly. Nanosheet optical anisotropy is observed spectroscopically by Raman and direction-dependent photoluminescence (PL) measurements. Resulting data indicate significantly lower PL emission due to optical excitation with electric field oscillation out of plane, parallel to the MoS2 c-axis, than that associated with perpendicular excitation, with the dichroic ratio I perp/I par = 3. The approach developed here provides a useful route to elucidate anisotropic optical properties of MoS2 nanosheets and to utilize such properties in new materials and devices.