Xu Hang, Hu Jiping, Wang Fang, Qu Yipu, Liu Yuhuai
National Center for International Joint Research of Electronic Materials and Systems, International Joint-Laboratory of Electronic Materials and Systems of Henan Province, College of Electrical and Information Engineering, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China.
Institute of Intelligence Sensing, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China.
Langmuir. 2024 Sep 10;40(36):19146-19154. doi: 10.1021/acs.langmuir.4c02310. Epub 2024 Aug 27.
Hexagonal boron nitride (h-BN) has attracted significant attention due to its exceptional properties. Among various substrates used for h-BN growth, diamond emerges as a more promising substrate due to its high-temperature resistance and superior electrical properties. To reveal the nucleation mechanism of h-BN on the diamond (111) surface and the impact of hydrogenation treatment on this process, we explored the adsorption, diffusion, nucleation morphologies, and predicted nucleation pathways in this process using first-principles calculations based on density functional theory (DFT). Our results indicate that N positioned above the first layer of C and B positioned above the second layer of C enhance the stability of BN clusters. During the growth of BN clusters, there is a geometric transformation from chain-like structures to honeycomb-like structures. The proportion of unhybridized sp atoms within BN clusters and geometric symmetry significantly influence h-BN growth. Moreover, computational findings also suggest that to enhance the nucleation rate of h-BN it is essential to inhibit the formation of zigzag chain structures by BN clusters during the early stages of nucleation on a clean diamond surface. Additionally, hydrogenation treatment decreases the binding affinity of B and N on the substrate, facilitating atomic diffusion, and has been identified as an effective approach to facilitate nucleation. Furthermore, hydrogen-terminated diamond acts as an electron donor in the system, which profoundly affects the morphology of growing h-BN and the characteristics of the h-BN/diamond heterostructures. These conclusions are important to understanding and optimizing h-BN growth on diamond and provide a theoretical basis of the construction and application of the h-BN/diamond heterostructure.
六方氮化硼（h-BN）因其优异的性能而备受关注。在用于h-BN生长的各种衬底中，金刚石因其耐高温性和优异的电学性能而成为更有前景的衬底。为了揭示h-BN在金刚石（111）表面的成核机制以及氢化处理对该过程的影响，我们基于密度泛函理论（DFT）使用第一性原理计算探索了该过程中的吸附、扩散、成核形态以及预测的成核途径。我们的结果表明，位于第一层C上方的N和位于第二层C上方的B增强了BN团簇的稳定性。在BN团簇的生长过程中，存在从链状结构到蜂窝状结构的几何转变。BN团簇内未杂化的sp原子比例和几何对称性对h-BN的生长有显著影响。此外，计算结果还表明，为了提高h-BN的成核速率，在清洁金刚石表面成核的早期阶段抑制BN团簇形成锯齿形链结构至关重要。此外，氢化处理降低了B和N在衬底上的结合亲和力，促进了原子扩散，并且已被确定为促进成核的有效方法。此外，氢终止的金刚石在系统中充当电子供体，这深刻影响了生长中的h-BN的形态以及h-BN/金刚石异质结构的特性。这些结论对于理解和优化h-BN在金刚石上的生长非常重要，并为h-BN/金刚石异质结构的构建和应用提供了理论基础。
