Chemistry of semiconductor clusters: Large silicon clusters are much less reactive towards oxygen than the bulk
Chemistry of semiconductor clusters: Large silicon clusters are much less reactive towards oxygen than the bulk
复制标题
半导体团簇的化学性质：大的硅团簇对氧的反应性比块体小得多
DOI：
10.1063/1.459595
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
K. Creegan
中科院分区：
文献类型：
--
作者：
M. Jarrold;U. Ray;K. Creegan
使用选定的离子漂移管技术研究了 Si+n (n=10–65) 与 O2 的化学反应。较小的簇被 O2 蚀刻，得到 Si+n−2（和两个 SiO 分子），较大的簇化学吸附氧，形成 SinO+2 加合物。在所采用的条件下，转变发生在n=29和36之间。较小团簇的反应性存在很大差异：Si+13、Si+14 和 Si+23 特别惰性。随着簇尺寸的增加，反应性的变化迅速减弱，对于具有 40-65 个原子的簇，反应性几乎与尺寸无关。然而，这些大团簇对 O2 的反应性比大多数块状硅表面低约 102 倍。对反应温度依赖性的研究表明，它们通过亚稳态前体进行，该状态可能是物理吸附到簇表面的分子 O2。解离化学吸附活化势垒大小的变化导致了团簇反应性的变化...
The chemical reactions of Si+n (n=10–65) with O2 have been investigated using selected ion drift tube techniques. The smaller clusters are etched by O2 to give Si+n−2 (and two SiO molecules) and the larger clusters chemisorb oxygen forming an SinO+2 adduct. The transition occurs between n=29 and 36 under the conditions employed. There are large variations in the reactivity of the smaller clusters: Si+13, Si+14, and Si+23 are particularly inert. The variations in reactivity are rapidly damped with increasing cluster size and for clusters with 40–65 atoms the reactivity is nearly independent of size. However, these large clusters are ∼102 times less reactive towards O2 than most bulk silicon surfaces. Studies of the temperature dependence of the reactions reveal that they proceed through a metastable precursor state which is probably molecular O2 physisorbed to the cluster surface. Variations in the size of the activation barrier for dissociative chemisorption account for the changes in reactivity with clus...