First-principles investigation of oxygen-excess defects in amorphous silica
First-principles investigation of oxygen-excess defects in amorphous silica
复制标题
无定形二氧化硅中氧过量缺陷的第一性原理研究
DOI：
10.1063/1.4998280
复制
发表时间：
2017-10-01
期刊：
影响因子：
1.6
通讯作者：
Zuo, Xu
中科院分区：
文献类型：
--
作者：
Chen, Zehua;Wang, Jian-wei;Zuo, Xu
利用从头算方法，研究了中性过剩氧原子与无定形二氧化硅(a-SiO_2)之间的相互作用，以及中性过剩氧缺陷上的空穴陷阱。计算表明，过量氧与a-SiO_2网络的相互作用导致了两种不同的缺陷结构，称为氧桥键(OBB)和过氧键构型。在捕获空穴后，OBB构型可能松弛到较低的能量结构，代表了通往过氧基(POR)缺陷的潜在弛豫通道。计算的超精细参数与POR缺陷实验符合得很好，表明捕获未配对自旋的氧原子只与一个硅原子结合。这意味着OBB构型是POR缺陷的主要前驱。
Using ab initio calculations, we investigate the interactions among neutral excess oxygen atoms and amorphous silica (a-SiO2), along with hole trapping on neutral excess-oxygen defects. The calculations demonstrate that the interaction of excess oxygen with the a-SiO2 network results in two distinct defect structures referred to as the oxygen bridge-bonded (OBB) and peroxy linkage configurations. The OBB configuration may relax to a lower-energy structure after trapping a hole, representing a potential relaxation channel to the peroxy radical (POR) defect. The calculated hyperfine parameters are in excellent agreement with POR defect experiments and show that the oxygen atoms trapping the unpaired spin are bound to only one silicon atom. This implies that the OBB configuration is the major precursor of POR defects.