Generalizable growth of 2D twisted transition metal dichalcogenide heterostructures under non-equilibrium thermodynamic conditions
摘要
Twisted two-dimensional (2D) transition metal dichalcogenide (TMD) structures have emerged as a versatile platform for optoelectronics and quantum materials, but their controlled bottom-up synthesis remains challenging. Here, we report a heating rate-controlled chemical vapor deposition method to grow various TMD heterostructures with improved control over the twist angle by enabling epitaxial growth during the heating process, rather than conventional isothermal stages. Specifically, a low heating rate (10 °C/min) is found to favor twist angles ≤ 22.5°, whereas a high rate (≥ 30 °C/min) promotes twist angles ≥ 30.0°. Theoretical analysis suggests that this strategy enhances high-energy molecular collisions and reduces kinetic energy barriers for the formation of 2D twisted TMD van der Waals (vdW) heterostructures. This method enables the synthesis of 18 different twisted TMD heterostructures. Systematic characterizations confirm twist-angle-dependent moiré periodicity and interlayer coupling correlation in these structures. Transient reflection (TR) in WSe2/WS2 bilayers reveal a non-monotonic carrier lifetime modulation, prolonged at intermediate angles. Our study provides a generalizable pathway for fabricating twisted vdW heterostructures.