Vertically Stacked Intraband Quantum Dot Devices for Mid-Wavelength Infrared Photodetection
Vertically Stacked Intraband Quantum Dot Devices for Mid-Wavelength Infrared Photodetection
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DOI：
10.1021/acsami.0c19450
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发表时间：
2021-01-13
影响因子：
9.5
通讯作者：
Ko, Dong-Kyun
中科院分区：
文献类型：
--
作者：
Hafiz, Shihab Bin;Al Mahfuz, Mohammad M.;Ko, Dong-Kyun
带内量子点是简并掺杂的半导体纳米材料，在中长波长红外区域表现出独特的光学特性。迄今为止，这些量子点仅作为横向光电导器件进行研究，而向垂直堆叠结构的过渡可以为研究先进器件设计提供多种机会。在这里，我们报道了第一个由 Ag2Se/PbS/Ag2Se 量子点堆叠组成的垂直带内量子点异质结器件，该器件具有降低暗电导率和简化器件制造过程的优点。我们讨论了对垂直器件制造至关重要的 Ag2Se 量子点胶体合成的改进，确定了决定量子点薄膜中波长红外响应度的重要工艺，并分析了基本器件特性和关键探测器性能参数。与上一代基于 Ag2Se 量子点的光电导器件相比，室温下中波长响应度提高了约 70 倍。
Intraband quantum dots are degenerately doped semiconductor nanomaterials that exhibit unique optical properties in mid- to long-wavelength infrared. To date, these quantum dots have been only studied as lateral photoconductive devices, while transitioning toward a vertically stacked structure can open diverse opportunities for investigating advanced device designs. Here, we report the first vertical intraband quantum dot heterojunction devices composed of Ag2Se/PbS/Ag2Se quantum dot stacks that bring the advantage of reduced dark conductivity with a simplified device fabrication procedure. We discuss the improvement in the colloidal synthesis of Ag2Se quantum dots that are critical for vertical device fabrication, identify an important process that determines the mid-wavelength infrared responsivity of the quantum dot film, and analyze the basic device characteristics and key detector performance parameters. Compared to the previous generation of Ag2Se quantum dot-based photoconductive devices, approximately 70 times increase in the mid-wavelength responsivity, at room temperature, is observed.