First-principles calculations of boron-related defects in SiO 2
First-principles calculations of boron-related defects in SiO 2
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SiO 2 中与硼相关的缺陷的第一性原理计算
DOI：
10.1103/physrevb.68.184112
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发表时间：
2003
影响因子：
3.7
通讯作者：
A. Oshiyama
中科院分区：
文献类型：
--
作者：
M. Otani;K. Shiraishi;A. Oshiyama
我们报道了第一原理总能量计算，给出了硼在含有O空位和O间隙的点缺陷的SiO_2中的稳定和亚稳态几何构型和扩散机制。我们发现，B原子在具有点缺陷的SiO_2中形成各种稳定的和亚稳态的几何构型，这取决于它的荷电状态和周围环境。我们还进行了计算，阐明了B原子与SiO_2中组成原子之间成键组态的化学可行性。结果表明，杂质周围的波函数分布及其占据是决定各电荷态几何构型的关键。B原子与SiO_2中各组成原子的结合能是决定B原子周围成键构型的重要因素。在具有O间隙的SiO_2中的B原子中，一个B原子形成一个非常稳定的B-O络合物，其中B原子与O间隙相结合。一旦B-O络合物形成，B原子通过SiO_2网络扩散，使这个B-O单元具有出人意料的2.1-2.3 eV的小激活能。计算的活化能与实验数据符合得很好。
We report first-principle total-energy calculations that provide stable and metastable geometries and diffusion mechanisms of boron in SiO 2 with point defects which contain O vacancies and O interstitials. We find that a B atom forms various stable and metastable geometries in SiO 2 with point defects, depending on its charge state and surrounding environments. We also perform calculations that clarify the chemical feasibility of bonding configurations between a B atom and constituent atoms in SiO 2 . It is found that wave function distribution around the impurity and its occupation are essential to determine the geometry for each charge state. Binding energies of a B atom with constituent atoms in SiO 2 are decisive factors to the bond configuration around the B atom. In the case of B in SiO 2 with an O interstitial, a B atom forms a very stable B-O complex in which the B atom is bound to the O interstitial. Once the B-O complex is formed, the B atom diffuses via the SiO 2 network keeping this B-O unit with unexpectedly small activation energies of 2.1-2.3 eV. The calculated activation energies agree well with the data experimentally available.