论文标题
MBE种植的GAAS-（GA，AL）AS-GA（AS，BI）核心壳纳米线中的BI掺入和隔离
Bi Incorporation and segregation in the MBE-grown GaAs-(Ga,Al)As-Ga(As,Bi) core-shell nanowires
论文作者
论文摘要
用透射电子显微镜研究了将BI掺入由分子束外延生长的GAAS-（GA，AL）AS-GA（AS，BI）核心壳纳米线。纳米线在具有Au-Droplet辅助模式的GAAS（111）B基材上生长。在低温（300°C）下生长双型壳，接近化学计量的GA/AS通量比。在低BI通量下，GA（AS，BI）壳是光滑的，BI完全合并到壳中。较高的BI通量（BI/AS AS AS通量比〜4％）导致BI作为纳米式侧壁上的液滴部分分离，该液滴优先位于具有Wurtzite结构的纳米线段。我们证明了侧壁上的这种BI液滴是垂直于GAAS树干的分支生长的催化剂。由于通过改变纳米线生长条件之间的锌 - 蓝色和wurtzite多型型之间的可调性，因此该效果使分支的纳米线体系结构具有由所选（Wurtzite）纳米线段产生的分支。
Incorporation of Bi into GaAs-(Ga,Al)As-Ga(As,Bi) core-shell nanowires grown by molecular beam epitaxy is studied with transmission electron microscopy. Nanowires are grown on GaAs(111)B substrates with Au-droplet assisted mode. Bi-doped shells are grown at low temperature (300 °C) with a close to stoichiometric Ga/As flux ratio. At low Bi fluxes, the Ga(As,Bi) shells are smooth, with Bi completely incorporated into the shells. Higher Bi fluxes (Bi/As flux ratio ~ 4%) led to partial segregation of Bi as droplets on the nanowires sidewalls, preferentially located at the nanowire segments with wurtzite structure. We demonstrate that such Bi droplets on the sidewalls act as catalysts for the growth of branches perpendicular to the GaAs trunks. Due to the tunability between zinc-blende and wurtzite polytypes by changing the nanowire growth conditions, this effect enables fabrication of branched nanowire architectures with branches generated from selected (wurtzite) nanowire segments.
