Wang Mingyuan, Liu Guiwu, Lei Shuangying, Wan Neng
Key Laboratory of MEMS of Ministry of Education, School of Integrated Circuits, Southeast University, Nanjing, 210096, China.
School of Materials Science and Engineering, Jiangsu University, Zhenjiang, 212013, China.
Phys Chem Chem Phys. 2024 Jul 3;26(26):18459-18465. doi: 10.1039/d4cp01930j.
During the process of synthesizing h-BN on Cu foil chemical vapor deposition (CVD), low-pressure CVD (LPCVD) typically synthesizes monolayer h-BN films, whereas atmospheric pressure CVD (APCVD) yields few-layer h-BN films. Herein, a growth mechanism for monolayer and few-layer h-BN on Cu foil is proposed using first-principles calculations: Cu(111) passivated h-BN hinders the diffusion of B and N atoms at the subsurface of Cu(111), preventing sufficient transportation of B and N atoms to the existing h-BN layer, thereby leading to the formation of monolayer h-BN in LPCVD. For APCVD, the edges of h-BN are passivated by H, which decreases the barrier energy for the diffusion of B and N atoms on the Cu(111) subsurface, and B and N atoms can easily migrate from the subsurface of Cu(111) to its surface, resulting in the nucleation of h-BN between the existing h-BN and Cu(111), and leading to the formation of few-layer h-BN films. This work provides a theoretical basis at the atomic scale for further understanding the growth of monolayer and few-layer h-BN films on Cu foil.
在铜箔上通过化学气相沉积（CVD）合成六方氮化硼（h-BN）的过程中，低压化学气相沉积（LPCVD）通常合成单层h-BN薄膜，而常压化学气相沉积（APCVD）则生成少层h-BN薄膜。在此，利用第一性原理计算提出了铜箔上单层和少层h-BN的生长机制：铜（111）钝化的h-BN阻碍了铜（111）亚表面上硼（B）和氮（N）原子的扩散，阻止了B和N原子向现有h-BN层的充分传输，从而导致在LPCVD中形成单层h-BN。对于APCVD，h-BN的边缘被氢（H）钝化，这降低了B和N原子在铜（111）亚表面扩散的势垒能量，并且B和N原子可以很容易地从铜（111）的亚表面迁移到其表面，导致在现有h-BN和铜（111）之间形成h-BN晶核，进而形成少层h-BN薄膜。这项工作为进一步理解铜箔上单层和少层h-BN薄膜的生长提供了原子尺度的理论基础。
