Chemically selective adsorption of molecular oxygen on GaAs(100)c(2×8)
Chemically selective adsorption of molecular oxygen on GaAs(100)c(2×8)
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GaAs(100)c(2×8)上分子氧的化学选择性吸附
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
A. Kummel
中科院分区：
文献类型：
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作者：
P. Kruse;James G. McLean;A. Kummel
利用扫描隧道显微镜（STM）对技术上重要的富as GaAs(100)c（2×8）表面的分子氧的化学吸附位点进行了成像。氧原子插入砷-镓背键，随后取代二聚体排中的砷原子。被置换的砷原子聚集成越来越大的团簇，形成金属砷。电负性强的氧原子最初被砷原子上较大的电子密度所吸引，但氧原子与镓原子的反应在热力学上是有利的。这导致氧插入As-Ga背键的化学选择性为100%，随后氧原子被化学吸附到砷位点。
The chemisorption sites of molecular oxygen on the technologically important As-rich GaAs(100)c(2×8) surface were imaged with scanning tunneling microscopy (STM). The oxygen atoms insert into the arsenic–gallium backbonds and, subsequently, replace the arsenic atoms in the dimer rows. The displaced arsenic atoms aggregate in clusters of increasing size forming metallic arsenic. The strongly electronegative oxygen atoms are initially attracted by the larger electron density at the arsenic atoms, but the reaction of the oxygen atoms with the gallium atoms is thermodynamically favored. This leads to a 100% chemical selectivity for oxygen insertion into the As–Ga backbonds and subsequent chemisorption of the oxygen atoms into the arsenic sites.