The Influence of B, N and Si Doping on the CH3 Adsorption on the Diamond Surface Based on DFT Calculations

Abstract

To better understand the influence mechanism of boron, nitrogen and silicon dopants on the growth of chemical vapor deposition (CVD) diamond film, density functional calculations have been performed to reveal the different impact of the impurities on the CH3 adsorption on diamond surface. The substituted doping and radical doping of diamond (111) and (100) − 2 × 1 surface are both considered. The calculation results indicate that the CH3 radicals are hardly adsorbed on nitrogen atoms and thus may cause vacancy in the diamond lattice easily. Boron substituted doping will disfavor the adsorption of CH3 due to the lacking of valence electron. However, the empty p orbitals of boron atom will help the chemical adsorbing of CH3 radicals. The substituted silicon doping has little influence on the CH3 adsorption, as Si atom has the same outer valence electron structure with C atom. In the case of radical doping, the adsorption energy of CH3 will be reduced due to the steric hindrance between NH2 or SiH3 with CH3. The adsorption energy can be slightly enhanced when BH2 radical is pre-adsorbed on diamond (111) surface. However, the BH2 pre-adsorbed on diamond (100) − 2 × 1 surface may interact with surface radical carbon site and result in a large reduction of CH3 adsorption energy. Thus, the boron doping may hinder the formation of the (100) facet during the CVD diamond deposition under a certain condition.

Study on the Growth Mechanism of Chlorocarbon Radicals on the Surface of CVD Diamond (100)

“…Through structural optimization and surface reconstruction [8], the six-layered diamond (100) had one hydrogen per carbon passivation layer on the surface and two hydrogens per fixed carbon on the bottom to maintain sp 3 hybridization. The corresponding reaction energies are very close for four-, six-, and eight-layer models, respectively, suggesting that the six-layer model represents the best compromise between size and accuracy which also used by Wang et al [11]. To confirm surface size independence for the reaction energies of H2 abstraction from the dimer, two different surface sizes were tested, namely, 4 × 2 and 2 × 2.…”

Nitrogen-doped sp3carbon dot catalysed two-electron electrochemical oxygen reduction for efficient production of hydrogen peroxide

“…It is widely acknowledged in academia that the binding energy of reaction intermediates (*OOH, *OH, and *O) regulates the catalytic activity of 2e − /4e − ORR electrocatalysts. 51–54…”

“…It is widely acknowledged in academia that the binding energy of reaction intermediates (*OOH, *OH, and *O) regulates the catalytic activity of 2e − /4e − ORR electrocatalysts. [51][52][53][54] The binding strength of *OOH intermediates to the active sites, in particular, is commonly applied as a signicant indicator to describe the selective activity of the catalyst, as shown in Fig. S14 (ESI †).…”

Ligand-Modified Boron-Doped Diamond Surface: DFT Insights into the Electronic Properties of Biofunctionalization

“…Similar DOS spectra indicating the formation of B-related acceptor impurity band were reported by Ashcheulov et al [50] by using B dimer supercells configuration or by Wang at el. [52] applying boron substituted doping. Apparently, the Monte Carlo method was applied to estimate band gap of semiconducting boron-doped diamond [53,54].…”