Systematic studies for improving device performance of quantum well infrared stripe photodetectors
Systematic studies for improving device performance of quantum well infrared stripe photodetectors
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DOI：
10.1515/nanoph-2020-0095
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发表时间：
2020-09-01
期刊：
影响因子：
7.5
通讯作者：
Miyazaki, Hideki T.
中科院分区：
文献类型：
--
作者：
Hainey, Mel F., Jr.;Mano, Takaaki;Miyazaki, Hideki T.
量子阱红外光电探测器与等离子体腔的集成使得可以在中红外至室温操作条件下演示灵敏的光电探测器。然而，尚未制定优化这些探测器的设备结构的明确指南。使用简单的条带腔探测器作为模型系统，我们阐明了提高光电探测器性能的基本因素。通过蚀刻条带之间的半导体材料，腔谐振波长预计会发生蓝移，电场预计会大幅增加，从而比未蚀刻的条带探测器具有更高的响应率。与我们的预测相反，蚀刻条纹探测器显示出较低的响应度，表明侧壁的表面效应和吸收减少。然而，由于显着减少了探测器暗电流，蚀刻导致了更高的探测率。这些结果表明蚀刻结构是优越的光电探测器设计，并且适当的侧壁表面处理可以进一步提高器件性能。最后，通过条纹探测器的偏振和入射角依赖性测量，我们阐明了先前演示的有线贴片天线的设计如何提高设备性能。这些结果广泛适用于红外范围内广泛波长的腔体设计，并且可以作为改进下一代红外光电探测器的路线图。
The integration of quantum well infrared photodetectors with plasmonic cavities has allowed for demonstration of sensitive photodetectors in the mid-infrared up to room-temperature operating conditions. However, clear guidelines for optimizing device structure for these detectors have not been developed. Using simple stripe cavity detectors as a model system, we clarify the fundamental factors that improve photodetector performance. By etching semiconductor material between the stripes, the cavity resonance wavelength was expected to blue-shift, and the electric field was predicted to strongly increase, resulting in higher responsivity than unetched stripe detectors. Contrary to our predictions, etched stripe detectors showed lower responsivities, indicating surface effects at the sidewalls and reduced absorption. Nevertheless, etching led to higher detectivity due to significantly reduced detector dark current. These results suggest that etched structures are the superior photodetector design, and that appropriate sidewall surface treatments could further improve device performance. Finally, through polarization and incidence angle dependence measurements of the stripe detectors, we clarify how the design of previously demonstrated wired patch antennas led to improved device performance. These results are widely applicable for cavity designs over a broad range of wavelengths within the infrared, and can serve as a roadmap for improving next-generation infrared photodetectors.