Electronic and dynamical properties of the silicon trivacancy
Electronic and dynamical properties of the silicon trivacancy
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硅三空位的电子和动力学特性
DOI：
10.1103/physrevb.86.174101
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发表时间：
2012
影响因子：
3.7
通讯作者：
Coutinho J
中科院分区：
文献类型：
--
作者：
Coutinho J
硅中的三空位(V)最近被证明是中性电荷态的双稳中心，具有四重协调构型V[FFC]，能量低于平面构型[V]。P. Markevich，物理学家[j].中国生物医学工程学报，2009,24(1):481 - 481。通过深度瞬态光谱测量和第一性原理密度泛函计算，报道了电子辐照Si:O晶体在等时等温退火过程中，v缺陷在不同构型之间的转变、扩散和消失。确定了平面构型向四重配位结构转变的激活能和相应的机制。退火研究表明，Vis在Si - atC和富氧材料中的迁移可以被间隙氧原子捕获，从而导致VO配合物的出现。计算表明，Vmotion是通过连续的FFC/平面变换步骤发生的。推导出了Vcenter的远程扩散活化能，计算结果与原子运动势垒一致。
The trivacancy (V) in silicon has been recently shown to be a bistable center in the neutral charge state, with a fourfold-coordinated configuration, V[FFC], lower in energy than theplanar one [V. P. Markevich , Phys. Rev. B 80, 235207 (2009)PRBMDO1098-012110.1103/PhysRevB.80.235207]. Transformations of the Vdefect between different configurations, its diffusion, and disappearance upon isochronal and isothermal annealing of electron-irradiated Si:O crystals are reported from joint deep level transient spectroscopy measurements and first-principles density-functional calculations. Activation energies and respective mechanisms for Vtransformation from theplanar configuration to the fourfold-coordinated structure have been determined. The annealing studies demonstrate that Vis mobile in Si atC and in oxygen-rich material can be trapped by interstitial oxygen atoms so resulting in the appearance of VO complexes. The calculations suggest that Vmotion takes place via consecutive FFC/planar transformation steps. The activation energy for the long-range diffusion of the Vcenter has been derived and agrees with atomic motion barrier from the calculations.