کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5006064 1461382 2017 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of VLS and VS mechanisms during shell growth in GaAs-AlGaAs core-shell nanowires investigated by transmission electron microscopy
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی برق و الکترونیک
پیش نمایش صفحه اول مقاله
Effects of VLS and VS mechanisms during shell growth in GaAs-AlGaAs core-shell nanowires investigated by transmission electron microscopy
چکیده انگلیسی
We investigated by means of transmission electron microscopy (TEM) the final growth stage of GaAs/AlGaAs core-shell nanowires (NWs) self-assembled by Au-catalyst assisted metalorganic vapor phase epitaxy (MOVPE). TEM observations and energy dispersive x-ray spectroscopy revealed the presence of an AlGaAs tapered region of varying chemical composition nearby the NW extreme end (i.e. between the core-shell NW trunk and the Au nanoparticle catalyst). Our findings evidence that this region exhibits an unintentional AlyGa1−yAs/AlxGa1−xAs core-shell structure, a result of the combined axial (vapor-liquid-solid, VLS) self-assembly and conventional (vapor-solid, VS) overgrowth of the material. While the VS-grown AlxGa1−xAs alloy retains the Al composition (x=0.3) of the AlGaAs shell along the NW trunk, the central AlyGa1−yAs section is made of an Al-rich (y≈0.8-0.9) alloy segment formed during AlGaAs shell overgrowth, followed by a graded-alloy segment formed upon deposition of the terminating GaAs cap layer, the latter segment due to the effect of the Al reservoir left in the Au catalyst nanoparticle (NP).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science in Semiconductor Processing - Volume 65, July 2017, Pages 108-112
نویسندگان
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