In the present article, we are introducing a novel heterogeneously coupled InAs Submonolayer (SML) on Stranski-Krastanov (SK) quantum dot (QD) heterostructure with reduced strain accumulation. Theoretical comparison manifests the superiority of this hybrid SML-SK QDs over bilayer SK QDs. Photoluminescence and photoluminescence excitation spectroscopy are employed to characterize the electronic interaction and carrier tunneling in between this hybrid quantum dot assembly. Growth rate is optimized at 0.1 ML/sec. To tune the coupling, the barrier layer thickness is varied from 5 nm to 10 nm. Even up to the highest barrier thickness, no signature of SML peak is obtained in the PL response. But, PLE depicts the presence of SML peak, which is partially overlapped with the SK 2nd excited peak. The sample with 7.5 nm GaAs barrier shows perfect resonance between SML ground state and SK 2nd excited state. Based on experimental and analytical results, this SML on SK (SML-SK) configuration is compared with SK on SML (SK-SML) configuration; where SML-SK exhibits better inter dot electronic interaction than its reciprocal configuration. For ex situ tailoring of this heterogeneous electronic coupling, rapid thermal annealing has been done. It shows tunability of inter dot interaction with improved crystalline quality. Finally, we have shown a SML-SK quantum dot infrared photodetector with a broad spectral response (from SWIR to near LWIR).

中文翻译：

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InAs Stranski-Krastanov 量子点异质结构上的垂直耦合混合 InAs 亚单层：面向下一代宽带红外检测

在本文中，我们将在 Stranski-Krastanov (SK) 量子点 (QD) 异质结构上引入一种新型异质耦合 InAs 亚单层 (SML)，可减少应变积累。理论比较表明这种混合 SML-SK QD 优于双层 SK QD。采用光致发光和光致发光激发光谱来表征这种混合量子点组件之间的电子相互作用和载流子隧穿。增长率优化为 0.1 ML/秒。为了调整耦合，阻挡层厚度从 5 nm 到 10 nm 不等。即使达到最高的势垒厚度，在 PL 响应中也没有获得 SML 峰的特征。但是，PLE 描述了 SML 峰的存在，它与 SK 2nd 激发峰部分重叠。样品与 7。5 nm GaAs 势垒显示了 SML 基态和 SK 第二激发态之间的完美共振。根据实验和分析结果，将此 SML on SK (SML-SK) 配置与 SK on SML (SK-SML) 配置进行比较；其中 SML-SK 表现出比其互易配置更好的点间电子相互作用。对于这种异质电子耦合的异位定制，已经完成了快速热退火。它显示了点间相互作用的可调性与改进的晶体质量。最后，我们展示了具有宽光谱响应（从 SWIR 到近 LWIR）的 SML-SK 量子点红外光电探测器。其中 SML-SK 表现出比其互易配置更好的点间电子相互作用。对于这种异质电子耦合的异位定制，已经完成了快速热退火。它显示了点间相互作用的可调性与改进的晶体质量。最后，我们展示了具有宽光谱响应（从 SWIR 到近 LWIR）的 SML-SK 量子点红外光电探测器。其中 SML-SK 表现出比其互易配置更好的点间电子相互作用。对于这种异质电子耦合的异位定制，已经完成了快速热退火。它显示了点间相互作用的可调性与改进的晶体质量。最后，我们展示了具有宽光谱响应（从 SWIR 到近 LWIR）的 SML-SK 量子点红外光电探测器。