Systematic studies for improving device performance of quantum well infrared stripe photodetectors

Nanophotonics

article

Mel F. Hainey¹  Yukinaga Arai¹  Akitsu Shigetou¹  Hideki T. Miyazaki¹  Takaaki Mano¹  Takeshi Kasaya¹  Tetsuyuki Ochiai¹  Hirotaka Osato¹  Kazuhiro Watanabe¹  Yoshimasa Sugimoto¹  Takuya Kawazu¹ 

[1] National Institute for Materials Science

关键词: etching;    infrared photodetector;    intersubband transition;    metasurface;    plasmonic cavity;    quantum well;   

DOI  :  10.1515/nanoph-2020-0095

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

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.

【 授权许可】

CC BY