不同反应气氛下氢终止金刚石表面的活化性能

Surface Activation Properties of the Hydrogen-terminated Diamond in Different Reaction Atmospheres

为了探究金刚石沉积过程中不同反应气氛下萃取基团对金刚石表面活化的影响,基于金刚石的同质外延生长机理,采用第一性原理平面波赝势方法分析了三种萃取基团(H、OH、Cl)在氢终止的金刚石[100]表面的吸附难易程度;并通过过渡态搜索计算,获得了CH4/H2,CH4/H2/CH3COCH3,C2H5Cl/H2三种反应气氛下金刚石氢终止表面产生活性位点的反应热及活化能。经对比分析后发现,H、OH、Cl在氢终止金刚石表面的吸附能逐渐增强,且Cl萃取金刚石表面氢原子产生活性空位的能垒最低。因而,在传统的CH4/H2气氛中引入氧元素或氯元素能有效降低金刚石表面活化所需的能量。

In order to study the effect of the extraction groups on the activation of diamond surface in different reaction atmospheres during diamond deposition,based on the mechanism of diamond homoepitaxial growth,the first principle pseudo-potential plane wave method was used to study the adsorption ease of the extraction groups(H,OH,Cl)on the hydrogen terminated diamond[100].Through the transition state search,the reaction heats and energy barriers of the generating active sites on the hydrogen-terminated diamond under CH4/H2,CH4/H2/CH3 COCH3 and C2 H5 Cl/H2 reaction atmospheres were obtained.After comparative analysis,it was found that the adsorption energy of H,OH and Cl is gradually enhanced,and the energy barrier of Cl extraction is the lowest.Based on the above conclusions,the introduction of oxygen or chlorine element in the traditional CH4/H2 atmosphere can reduce the energy required for diamond surface activation.