Universal production of anisotropic bilayer WSe2 nanoscrolls for high-performance photodetector

Abstract Transition metal dichalcogenide nanoscrolls (NSs) exhibit unique optoelectronic properties due to their spiral tubular structures. In this study, we successfully fabricated WSe 2 NSs with various morphologies, illustrating the evolution from planar to NS via an internal strain-driven rolling process. The anisotropic optical properties of the NSs were systematically analyzed by angle-resolve polarized Raman spectroscopy. For NSs with different rollup angles, the strain distribution is manifested by the variation of Raman intensity on the linear axis. In addition, the on/off ratio and detectivity of device based on bilayer NS reach 5.3 × 10 4 and 2.63 × 10 9 Jones, caused by the ultralow dark photocurrent. In summary, our study demonstrates a universal method for producing polymorphic products, demonstrating that bilayer WSe 2 NSs hold significant potential as a platform for fundamental research and technological applications.