Droplet etched GaAs quantum dots close to surfaces and metallic interfaces
Droplet etched GaAs quantum dots close to surfaces and metallic interfaces
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DOI：
10.1063/1.4974965
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发表时间：
2017-01-28
影响因子：
3.2
通讯作者：
Hansen, W.
中科院分区：
文献类型：
--
作者：
Heyn, Ch.;Zocher, M.;Hansen, W.
研究了具有薄盖层的GaAs量子点作为具有金属纳米结构（MN）的自对准混合物的构建块。这两种成分被填充到一个纳米孔模板钻到AlGaAs表面的自组装局部液滴蚀刻在分子束外延。在第一系列的样品中，使用微光致发光（PL）光谱研究了在不同的距离的近AlGaAs表面与单个QD的相互作用。随着距离减小到12.5 nm，表面电荷引起激子辐射寿命的增加，带电激子的形成和激子PL峰的加宽。PL峰展宽的定量分析的基础上的分析模型假设的表面电荷的时间波动。在第二样品系列中，纳米孔另外填充有Au纳米结构。光谱类似于没有金属的QD的光谱，但具有稍强的PL峰展宽。对于一个小的距离12.5 nm清楚地在光学近场的MN，量子点显示出典型的PL线宽为430 μ eV，仍然是足够小，以分离不同的激子线。出版社：AIP Publishing
GaAs quantum dots (QDs) with a thin cap layer are studied as building blocks for self-aligned hybrids with a metallic nanostructure (MN). Both constituents are filled into a nanohole template that is drilled into an AlGaAs surface by self-assembled local droplet etching during molecular beam epitaxy. In a first series of samples, the interaction of a near AlGaAs surface with a single QD at varied distance is studied using microphotoluminescence (PL) spectroscopy. With decreasing distance down to 12.5 nm, surface charges cause an increase in the exciton radiative lifetime, the formation of charged excitons, and a broadening of the exciton PL peaks. The PL peak broadening is quantitatively analyzed on the basis of an analytical model assuming temporal fluctuations of the surface charge. In a second sample series, the nanoholes are filled in addition with an Au nanostructure. The optical spectra are similar to those from QDs without a metal but with a slightly stronger PL peak broadening. For a small distance of 12.5 nm clearly within the optical near-field of the MN, the QDs show a typical PL linewidth of 430 mu eV that is still small enough to separate different excitonic lines. Published by AIP Publishing.