Schulpen Jeff J P M, Basuvalingam Saravana B, Verheijen Marcel A, Bol Ageeth A
Department of Applied Physics and Science Education, Eindhoven University of Technology, Eindhoven 5600 MB, the Netherlands.
Eurofins Materials Science BV, High Tech Campus, Eindhoven 5656 AE, the Netherlands.
Nanoscale. 2025 Jul 16;17(28):16922-16927. doi: 10.1039/d5nr01013f.
3D nanostructures are a vital part of various applications envisaged for two-dimensional transition metal dichalcogenides (2D TMDs), such as nanoelectronics and catalysis. However, achieving conformal deposition of 2D TMD films on 3D nanostructures is challenging due to the requirement for bending the basal planes of the 2D TMDs. Here, the limits of conformality of 2D WS deposited by atomic layer deposition on SiO 3D nanostructures are investigated through cross-sectional transmission electron microscopy imaging. A minimum radius of curvature of 4 nm is identified above which basal plane conformality is almost always observed, while for smaller radii conformality is only observed in approximately half of the cases. We show that the observed tipping point agrees with the balance between the adhesion and stiffness forces, which allows for the estimation of the critical radius of curvature for other 2D TMDs and substrates. These results provide guidelines for the design of 3D nanostructured devices and substrates on which conformality of 2D materials is desired.
三维纳米结构是二维过渡金属二硫属化物（2D TMDs）在纳米电子学和催化等各种设想应用中的重要组成部分。然而，由于需要弯曲二维TMDs的基面，在三维纳米结构上实现二维TMD薄膜的保形沉积具有挑战性。在此，通过横截面透射电子显微镜成像研究了原子层沉积在SiO三维纳米结构上的二维WS保形性的极限。确定了最小曲率半径为4纳米，高于该半径时几乎总能观察到基面保形性；而对于较小半径，仅在大约一半的情况下观察到保形性。我们表明，观察到的临界点与粘附力和刚度力之间的平衡一致，这使得能够估计其他二维TMDs和衬底的临界曲率半径。这些结果为设计期望二维材料具有保形性的三维纳米结构器件和衬底提供了指导。
