Strong Anisotropic Optical Properties by Rolling up MoS 2 Nanoflake.

Although anisotropic two-dimensional materials have attracted great scientific interest, the anisotropy of those materials is limited to particular crystallographic directions. Herein, with dimension confining, MoS 2 nanoscrolls are successfully fabricated by a rolling-up process after dropping an ethanol-water solution on a chemical vapor deposition-grown MoS 2 monolayer. The anisotropic vibrational and optical properties are systematically studied by angle-resolved polarized spectroscopy, including Raman, photoluminescence, and reflection measurements. Upon comparing the photoluminescence results between MoS 2 nanoscrolls and nanosheets, an obvious PL quenching phenomenon is observed, indicating the efficient separation of photon-induced carriers. Moreover, the time-resolved PL test identifying the lifetime of the carriers is decreased to 303 ps in the nanoscrolls, indicating a higher carrier-transfer efficiency. In summary, our work demonstrates the strong anisotropic optical properties of MoS 2 nanorolls, showing the nanoscrolls are a promising candidate for the fabrication of multifunctional devices.