论文标题
$ \ text {cu} _ {x} \ text {bi} _2 \ text {se} _3 $在环境压力环境中的铜迁移和表面氧化
Copper migration and surface oxidation of $\text{Cu}_{x}\text{Bi}_2\text{Se}_3$ in ambient pressure environments
论文作者
论文摘要
化学修饰（例如插入）可用于修饰表面特性或进一步使拓扑绝缘体的表面状态功能化。使用环境压力X射线光电子光谱，我们报告了$ \ text {cu} _ {x} \ text {bi} _2 \ text {se} _3 $中的铜迁移，该{bi} _2 \ text {se} _3 $在初始表面切割后的几个小时到几个小时内发生。近地表铜的增加以及样品表面的氧化以及硒含量的巨大变化。这些复杂的变化是通过核心水平光谱模拟进一步建模的，这表明表面附近的组成梯度随氧气暴露而发展。我们的结果阐明了一种新现象，该现象必须考虑到插入式拓扑绝缘子$ \ unicode {x2014} $和一般$ \ unicode {x2014} $中的插入材料，当标本暴露于环境条件时，表面化学成分可能会改变。
Chemical modifications such as intercalation can be used to modify surface properties or to further functionalize the surface states of topological insulators. Using ambient pressure X-ray photoelectron spectroscopy, we report copper migration in $\text{Cu}_{x}\text{Bi}_2\text{Se}_3$, which occurs on a timescale of hours to days after initial surface cleaving. The increase in near-surface copper proceeds along with the oxidation of the sample surface and large changes in the selenium content. These complex changes are further modelled with core-level spectroscopy simulations, which suggest a composition gradient near the surface which develops with oxygen exposure. Our results shed light on a new phenomenon that must be considered for intercalated topological insulators$\unicode{x2014}$and intercalated materials in general$\unicode{x2014}$that surface chemical composition can change when specimens are exposed to ambient conditions.
