LIFETIME AND SCREENING OF THE C1S PHOTOEMISSION IN GRAPHITE
LIFETIME AND SCREENING OF THE C1S PHOTOEMISSION IN GRAPHITE
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DOI：
10.1103/physrevb.41.9766
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发表时间：
1990-05-15
影响因子：
3.7
通讯作者：
CHEN, CT
中科院分区：
文献类型：
--
作者：
SETTE, F;WERTHEIM, GK;CHEN, CT
分析了石墨C1s线的高分辨软X射线光电子能谱，确定了对线宽和线形的各种贡献。自然寿命宽度Γ为210 meV，比小分子的寿命宽度（Γ = 110 meV）或孤立碳原子的寿命宽度（Γ= 56 meV）大得多。声子宽度不大于50 meV。从孤立原子到小分子和固体的俄歇衰变率增强的总体趋势表明原子间俄歇过程的重大贡献。然而，从分子到固体的宽度的大幅增加必须是由于另一种现象，也许是由于固体中激子终态的形成。我们的线形分析证实，该线具有与金属屏蔽相关的不对称性，这与石墨中的激子终态有关，但奇异性指数明显小于先前分析中获得的指数。
High-resolution soft-x-ray photoemission spectra of the C 1s line of graphite have been analyzed to determine the various contributions to the linewidth and line shape. The natural lifetime width Γ is 210 meV, much larger than those of small molecules (for which Γ≃ 110 meV), or that calculated for the isolated carbon atom (for which Γ= 56 meV). The phonon width is no larger than 50 meV. The general trend toward an enhanced Auger decay rate from the isolated atom to the small molecule and solid is indicative of significant contributions from interatomic Auger processes. However, the large increase in width from molecules to solids must be due to another phenomenon, perhaps to the formation of the excitonic final state in the solids. Our line-shape analysis confirms that the line has an asymmetry like that associated with metallic screening, which had been earlier related to the excitonic final state in graphite, but the singularity index is significantly smaller than that obtained in the previous analysis.