Highly Aligned Molybdenum Trioxide Nanobelts for Flexible Thin-Film Transistors and Supercapacitors: Macroscopic Assembly and Anisotropic Electrical Properties

One dimensional (1D) nanomaterials have attracted a lot of attention owing to its intriguing performance. However, cost-efficient macroscopic assembly of 1D nanomaterials into free-standing and well-aligned macroscopic structures that are anisotropic and highly ordered in microscopic appearance is still a challenge. Here, we report a general and versatile technology to directly assemble MoO3 nanobelts into macroscopic structures, including film and yarn, without using any extra functionalization agent or cross-linking agent. MoO3 nanobelts are close-packed as parallel arrays with longitudinal axes aligned perpendicular to the capillary force. Carrier mobility of aligned film along nanobelt axis and perpendicular directions are about 400 and 30 cm2/(V·s), respectively. The promising carrier mobility raised from its high-order alignment indicates potential application in thin film transistors. High degree order of assembled MoO3 yarn also enables large tensile strength of up to 120 MPa, which is superior to that of many similarly structured nature and artificial fibers/yarns.