GaAs1-xBix在GaAs闪锌矿/纤锌矿纳米线异质结构上的自选择生长
Self-selective growth of GaAs1-xBix on GaAs zinc blende/wurtzite nanowire heterostructures
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中文总结 AI 辅助
本研究以GaAs闪锌矿/纤锌矿纳米线异质结构为模板，通过阴离子交换实现GaAs1-xBix的自选择生长，发现闪锌矿段Bi浓度更高且抗氧化性更弱，为量子器件制备提供了可控模板。
中文摘要 AI 辅助
原子级的位点选择性纳米结构生长与材料掺入为量子材料和纳米器件的工程化提供了极具前景的途径。本研究采用具有闪锌矿（Zb）与纤锌矿（Wz）晶体相交替轴向异质结构的GaAs纳米线（NWs）作为位点选择性Ga和Bi过度生长的模板。借助具有纳米级空间分辨率的X射线光发射电子显微镜（XPEEM），我们绘制了元素分布与局部化学键，以揭示Bi原子在{110}Zb和{11-20}Wz晶面的掺入行为。Bi的掺入通过阴离子交换过程进行，Bi原子取代As原子，形成局部Ga-Bi键并生成薄的GaAs1-xBix壳层。我们观察到与晶体相相关的Bi掺入特性：在同一根纳米线中，Zb段的Bi浓度高于相邻的Wz段。此外，Bi含量较高的Zb段相较于Wz段抗氧化性更低，导致Wz表面的Ga氧化物含量增加。本研究凸显GaAs NW的Zb/Wz异质结构可作为可控生长GaBi和GaAs1-xBix纳米结构的模板，这类纳米结构具备可定制的功能，适用于量子应用领域。
英文摘要
Site-selective nanostructure growth and material incorporation at the atomic scale offer a promising pathway for engineering quantum materials and nanodevices. Here, GaAs nanowires (NWs) with an axial heterostructure of alternating zinc blende (Zb) and wurtzite (Wz) crystal phases are employed as templates for site-selective Ga and Bi overgrowth. Using X-ray photoemission electron microscopy (XPEEM) with nanoscale spatial resolution, we map elemental distribution and local chemical bonding to reveal the incorporation behavior of Bi atoms in {110} Zb and {11-20} Wz facets. Bi incorporation proceeds through an anion-exchange process, where Bi atoms replace As, forming local Ga-Bi bonds and producing a thin GaAs1-xBix shell. We observe crystal-phase-dependent Bi incorporation, with higher Bi concentration in the Zb segments than in the neighboring Wz segments within the same NW. Furthermore, the Zb segment with higher Bi content exhibits reduced susceptibility to oxidation compared with the Wz segment, resulting in increased Ga-oxide in the Wz surfaces. This study highlights GaAs NW Zb/Wz heterostructures as a template for controlled growth of GaBi and GaAs1-xBix nanostructures with tailored functionalities for quantum applications
