论文标题
在生长的几何形状中测得的单核纳米线的空间分辨的发光和晶体结构
Spatially-resolved luminescence and crystal structure of single core-shell nanowires measured in the as-grown geometry
论文作者
论文摘要
我们报告单个，生长的核心 - 甲基壳gaas/in $ _ {0.15} $ ga $ _ {0.85} $ as/gaas/gaas/alas/gaas纳米线之间的结构和光学特性之间的直接相关性。通过分子束外延在预制的SI（111）底物上制造，在一排良好的分离成核位点上，可以访问随着生长的几何形状中的单个纳米线。通过基于同步加速器的纳米螺旋桨X射线衍射技术监测轴向111 Bragg反射，沿纳米线的生长轴沿着纳米线的生长轴的多型分布。对于相同的纳米线，通过扫描电子显微镜中的阴极发光性高光谱线c，获得了空间分辨的发射特性。与两个测量值相关联，我们揭示了壳量子孔井发射能的蓝光，与纯晶体多型相比，具有交替的wurtzite和锌蓝色堆积的混合结构的片段的发射强度增加。通过横截面透射电子显微镜独立确认了这种混合结构的存在。
We report on the direct correlation between the structural and optical properties of single, as-grown core-multi-shell GaAs/In$_{0.15}$Ga$_{0.85}$As/GaAs/AlAs/GaAs nanowires. Fabricated by molecular beam epitaxy on a pre-patterned Si(111) substrate, on a row of well separated nucleation sites, it was possible to access individual nanowires in the as-grown geometry. The polytype distribution along the growth axis of the nanowires was revealed by synchrotron-based nanoprobe X-ray diffraction techniques monitoring the axial 111 Bragg reflection. For the same nanowires, the spatially-resolved emission properties were obtained by cathodoluminescence hyperspectral linescans in a scanning electron microscope. Correlating both measurements, we reveal a blueshift of the shell quantum well emission energy combined with an increased emission intensity for segments exhibiting a mixed structure of alternating wurtzite and zincblende stacking compared with the pure crystal polytypes. The presence of this mixed structure was independently confirmed by cross-sectional transmission electron microscopy.
