Control of Morphology and Substrate Etching in InAs/InP Droplet Epitaxy Quantum Dots for Single and Entangled Photon Emitters.
Control of Morphology and Substrate Etching in InAs/InP Droplet Epitaxy Quantum Dots for Single and Entangled Photon Emitters.
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DOI：
10.1021/acsanm.2c01197
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发表时间：
2022-06-24
影响因子：
5.9
通讯作者：
Koenraad, Paul M.
中科院分区：
文献类型：
--
作者：
Gajjela, Raja Sekhar Reddy;Sala, Elisa Maddalena;Heffernan, Jon;Koenraad, Paul M.
利用横截面扫描隧道显微镜(X-STM)对金属-有机气相外延生长的InAs/InP液滴外延量子点的形貌和衬底刻蚀机理进行了详细的原子分辨研究。根据结晶温度的不同，观察到两种不同的刻蚀过程：局部钻孔和远程刻蚀。在≤500°C的局部钻探中，In液滴局部液化下面的InP，P原子很容易从液滴扩散到边缘。在晶化过程中，As原子扩散到液滴中，在固液界面结晶，在量子点下方形成InAs蚀坑。在>；500°C的较高温度下进行的长程刻蚀中，InP层不稳定，来自周围环境的In原子向液滴迁移。P原子可以很容易地从表面逃逸到真空中，在量子点周围形成沟槽。我们首次用原子分辨率显示了InAs/InP量子点中沟槽和长程刻蚀的形成。这两种刻蚀过程都可以通过在液滴沉积之前生长一层薄薄的InGaAs层来抑制。通过有限元模拟结合X-STM对QD组分进行了估算。刻蚀引起的量子点形貌的变化对精细结构的分裂有很大的影响。因此，当前的原子分辨率研究揭示了InAs/InP液滴外延量子点的形貌和刻蚀行为随结晶温度的变化规律，为InAs/InP液滴外延量子点的形成提供了有价值的见解，在量子信息技术中具有潜在的应用前景。
We present a detailed atomic-resolution study of morphology and substrate etching mechanism in InAs/InP droplet epitaxy quantum dots (QDs) grown by metal–organic vapor phase epitaxy via cross-sectional scanning tunneling microscopy (X-STM). Two different etching processes are observed depending on the crystallization temperature: local drilling and long-range etching. In local drilling occurring at temperatures of ≤500 °C, the In droplet locally liquefies the InP underneath and the P atoms can easily diffuse out of the droplet to the edges. During crystallization, the As atoms diffuse into the droplet and crystallize at the solid–liquid interface, forming an InAs etch pit underneath the QD. In long-range etching, occurring at higher temperatures of >500 °C, the InP layer is destabilized and the In atoms from the surroundings migrate toward the droplet. The P atoms can easily escape from the surface into the vacuum, forming trenches around the QD. We show for the first time the formation of trenches and long-range etching in InAs/InP QDs with atomic resolution. Both etching processes can be suppressed by growing a thin layer of InGaAs prior to the droplet deposition. The QD composition is estimated by finite element modeling in combination with X-STM. The change in the morphology of QDs due to etching can strongly influence the fine structure splitting. Therefore, the current atomic-resolution study sheds light on the morphology and etching behavior as a function of crystallization temperature and provides a valuable insight into the formation of InAs/InP droplet epitaxy QDs which have potential applications in quantum information technologies.
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影响因子：
3.7
作者：
Heyn, Christian
通讯作者：
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影响因子：
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作者：
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DOI：
10.1109/2944.605656
发表时间：
1997-04-01
影响因子：
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作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
Koenraad, Paul M.
影响因子：
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作者：
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通讯作者：
Schmidt, O. G.