Narrow-Band 4.3μm Plasmonic Schottky-Barrier Photodetector for CO2 Sensing

• Published in: IEEE sensors letters Vol. 3; no. 3; pp. 1 - 4
• Main Authors: Vahdani, M., Yaraghi, S., Neshasteh, H., Shahabadi, M.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.03.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Absorption; Carbon dioxide; CMOS; Co2 sensor; Electromagnetic wave sensors; Gratings; Infrared radiation; narrow-band infrared (IR) detection; Periodic structures; Photodetectors; Photometers; Plasmons; Platinum; Platinum alloys; platinum silicide grating; Resonance; Schottky-barrier photodetecto; Silicides; Silicon
• ISSN: 2475-1472
• DOI: 10.1109/LSENS.2019.2895968

Using an embedded platinum silicide (PtSi) grating, a Schottky-barrier photodetector structure for narrow-band detection of mid-infrared (mid-IR) radiation is proposed and designed. Schottky-barrier photodetectors designed for the infrared wavelengths suffer from poor efficiency and photoresponse. We propose a photodetector based on PtSi-Si Schottky junction with increased interface area where hot carriers are more likely to cross the junction in favor of a higher photoresponse. Furthermore, a guided-mode resonance of the presented periodic structure is coupled to its Fabry-Pérot resonance to achieve narrow-band absorption. The proposed photodetector absorbs 84% of incident power at a wavelength of 4.3 μm with a full-width half-maximum bandwidth of 94 nm. High photoresponsivity and compatibility with complementary metal oxide semiconductor process render the proposed structure a low-cost photodetector in the mid-IR range for CO 2 sensing.