The ultrafast growth of large-area,high-quality WSe2 domains with a compact triangular morphology has recently been achieved on a gold substrate via chemical vapor deposition.However,the underlying mechanism responsib...The ultrafast growth of large-area,high-quality WSe2 domains with a compact triangular morphology has recently been achieved on a gold substrate via chemical vapor deposition.However,the underlying mechanism responsible for ultrafast growth remains elusive.Here,we first analyze growth processes and identify two possible pathways that might achieve ultrafast growth:Path 1,fast edge attachment and ultrafast edge diffusion;Path 2,fast kink nucleation and ultrafast kink propagation.We perform kinetic Monte Carlo simulations and first-principles calculations to assess the viability of these two paths,finding that Path 1 is not viable due to the high edge diffusion barrier calculated from first-principles calculations.Remarkably,Path 2 reproduces all the experimental growth features(domain morphology,domain orientation,and growth rate),and the associated energetic data are consistent with first-principles calculations.The present work unveils the underlying mechanism for the ultrafast growth of WSe2,and may provide a new route for the ultrafast growth of other two-dimensional materials.展开更多
基金The authors gratefully acknowledge the support from the Science and Engineering Research Council through grant(152-70-00017)use of computing resources at the A*STAR Computational Resource Centre and National Supercomputer Centre,Singapore.J.Gao also thanks the Start-Up grant of DUT(3005-852069).
文摘The ultrafast growth of large-area,high-quality WSe2 domains with a compact triangular morphology has recently been achieved on a gold substrate via chemical vapor deposition.However,the underlying mechanism responsible for ultrafast growth remains elusive.Here,we first analyze growth processes and identify two possible pathways that might achieve ultrafast growth:Path 1,fast edge attachment and ultrafast edge diffusion;Path 2,fast kink nucleation and ultrafast kink propagation.We perform kinetic Monte Carlo simulations and first-principles calculations to assess the viability of these two paths,finding that Path 1 is not viable due to the high edge diffusion barrier calculated from first-principles calculations.Remarkably,Path 2 reproduces all the experimental growth features(domain morphology,domain orientation,and growth rate),and the associated energetic data are consistent with first-principles calculations.The present work unveils the underlying mechanism for the ultrafast growth of WSe2,and may provide a new route for the ultrafast growth of other two-dimensional materials.
