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arXiv 0704.2168cond-mat.mtrl-sci
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固体中空穴俘获正电子态的能量学

Energetics of positron states trapped at vacancies in solids

I. Makkonen, M. J. Puska

摘要:

我们报告了正电子在金属和半导体中空位缺陷处俘获的计算第一性原理研究。主要强调的是能量的捕获过程中,包括正电子状态和缺陷的离子结构之间的相互作用,并在随后的湮没特性的捕获状态。对于共价半导体中的空位,离子弛豫是正电子捕获过程的关键部分,使得正电子状态能够局部化。然而,正电子俘获并不强烈地影响电子结构的特征,例如,电离水平仅适度变化。在金属空位的情况下,正电子诱导的离子弛豫对湮灭电子-正电子对的正电子寿命和动量分布也有明显的影响。

英文摘要:

We report a computational first-principles study of positron trapping at vacancy defects in metals and semiconductors. The main emphasis is on the energetics of the trapping process including the interplay between the positron state and the defect's ionic structure and on the ensuing annihilation characteristics of the trapped state. For vacancies in covalent semiconductors the ion relaxation is a crucial part of the positron trapping process enabling the localization of the positron state. However, positron trapping does not strongly affect the characteristic features of the electronic structure, e.g., the ionization levels change only moderately. Also in the case of metal vacancies the positron-induced ion relaxation has a noticeable effect on the calculated positron lifetime and momentum distribution of annihilating electron-positron pairs.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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