Migration behaviour of carbon atoms on clean diamond (001) surface: A first principle study
Migration behaviour of carbon atoms on clean diamond (001) surface: A first principle study
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洁净金刚石 (001) 表面上碳原子的迁移行为：第一原理研究
DOI：
10.1016/j.apsusc.2015.11.189
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发表时间：
2016
影响因子：
6.7
通讯作者：
Sun Shiyang
中科院分区：
文献类型：
--
作者：
Liu Xuejie;Xia Qing;Li Wenjuan;Luo Hao;Ren Yuan;Tan Xin;Sun Shiyang
为了研究超纳米金刚石（UNCD）薄膜的形成，采用基于密度泛函理论的第一性原理方法，计算了单个碳原子在清洁金刚石（001）表面的吸附能、迁移能和两个碳原子的构型演化能。单原子沿二聚体行沿着扩散的活化能为1.96 eV，与富氢条件下CH 2沿二聚体行沿着迁移的活化能几乎相同.然而，一个单原子扩散沿着二聚体链的活化能为2.66 eV，这是大约1.55倍，大于在富氢环境中的CH 2迁移沿着二聚体链。两个碳原子的构型演化在普通金刚石膜沉积温度（700-900 °C）下几乎是不可能的，因为活化能达到4.46或5.90 eV。因此，在贫氢CVD环境中，高能量势垒会导致吸附原子迁移不足，导致UNCD薄膜形成非晶。
The adsorption and migration energies of a single carbon atom and the configuration evolution energies of two carbon atoms on a clean diamond (0 0 1) surface were calculated using the first principle method based on density functional theory to investigate the formation of ultra-nanocrystalline diamond (UNCD) film. The activation energy of a single atom diffusing along a dimer row is 1.96 eV, which is almost the same as that of a CH2migrating along a dimer row under hydrogen-rich conditions. However, the activation energy of a single atom diffusing along a dimer chain is 2.66 eV, which is approximately 1.55 times greater than that of a CH2migrating along a dimer chain in a hydrogen-rich environment. The configuration evolution of the two carbon atoms is almost impossible at common diamond film deposition temperatures (700–900 °C) because the activation energies reach 4.46 or 5.90 eV. Therefore, the high-energy barrier could result in insufficient migration of adatoms, leading to the formation of amorphous in UNCD films in hydrogen-poor CVD environment.