论文标题
通过横截面扫描隧道显微镜在GAAS中研究的GAAS中的N-NH复合物
N-nH complexes in GaAs studied at the atomic scale by cross-sectional scanning tunneling microscopy
论文作者
论文摘要
氮（N）掺杂的GAA的氢化可以通过操纵N-NH-NH复合物，N-NH复合物的操纵来对带隙进行可逆调整，并创建位点受控的量子点，其中氮原子被N氢（H）原子包围。在这里，我们采用横截面扫描隧道显微镜（X-STM）在原子尺度上研究GAAS（110）表面的这些复合物。除此之外，我们还进行了密度功能理论（DFT）计算以确定N-NH复合物的原子特性。我们认为，在（110）GAAS表面表面或附近，N-NH复合物的两个H原子分离为H $ _2 $分子。我们观察到与氢化过程有关的多个特征，该过程将子集分类为N-1H复合物。这些与N-1H相关的特征显示，GAAS表面N原子的局部密度（LDOS）明显降低，并在位于三个晶体方向之一的LDO中具有额外的明显局部增强。 N-NH功能可以用STM尖端操纵。在一个情况下显示两个镜像对称状态之间的切换行为，在另一种情况下，删除了LDO的局部增强。明亮对比的消失很可能是从N-NH复合物中去除H原子的标志。
Hydrogenation of nitrogen (N) doped GaAs allows for reversible tuning of the bandgap and the creation of site controlled quantum dots through the manipulation of N-nH complexes, N-nH complexes, wherein a nitrogen atom is surrounded by n hydrogen (H) atoms. Here we employ cross-sectional scanning tunneling microscopy (X-STM) to study these complexes in the GaAs (110) surface at the atomic scale. In addition to that we performed density functional theory (DFT) calculations to determine the atomic properties of the N-nH complexes. We argue that at or near the (110) GaAs surface two H atoms from N-nH complexes dissociate as an H$_2$ molecule. We observe multiple features related to the hydrogenation process, of which a subset is classified as N-1H complexes. These N-1H related features show an apparent reduction of the local density of states (LDOS), characteristic to N atoms in the GaAs (110) surface with an additional apparent localized enhancement of the LDOS located in one of three crystal directions. N-nH features can be manipulated with the STM tip. Showing in one case a switching behavior between two mirror-symmetric states and in another case a removal of the localized enhancement of the LDOS. The disappearance of the bright contrast is most likely a signature of the removal of an H atom from the N-nH complex.
