Integrated Plasmonic Infrared Photodetector Based on Colloidal HgTe Quantum Dots

• Published in: Advanced materials technologies 2019-10, Vol.4 (10), p.n/a
• Main Authors: Zhu, Bingqing, Chen, Mengyu, Zhu, Qiang, Zhou, Guodong, Abdelazim, Nema M., Zhou, Wen, Kershaw, Stephen V., Rogach, Andrey L., Zhao, Ni, Tsang, Hon Ki
• Format: Article
• Language: English
• Subjects: colloidal quantum dots; infrared photodetectors; plasmonic waveguides; silicon photonics
• ISSN: 2365-709X; 2365-709X
• DOI: 10.1002/admt.201900354

This paper presents a 2300 nm wavelength photodetector which comprises a spin‐deposited colloidal HgTe quantum dot (QD) film on a metal‐insulator‐metal (MIM) plasmonic waveguide. This photodetector is an integrated device based on the complementary metal‐oxide‐semiconductor compatible silicon‐on‐insulator platform. The device employs input and output silicon waveguide grating couplers, and HgTe QDs are used as the infrared photosensing material. Infrared light is coupled to the strongly confined MIM waveguide mode, which shrinks the device footprint and improves the light detection efficiency simultaneously. A room temperature responsivity of 23 mA W−1 and a noise‐equivalent power of 8.7 × 10−11 W Hz−1/2 at 2300 nm wavelength are achieved by the photodetector at 2.14 W mm−2 (measured at the input to the plasmonic waveguide) with a device footprint of 15 µm × 0.35 µm. The light intensity–dependent photocurrent, the current noise spectral density, and the 3 dB operation bandwidth are all characterized. The charge transfer properties of the organic HgTe QD films are further analyzed based on field effect transistor measurements. A low‐noise integrated infrared photodetector operated at 2300 nm wavelength, comprising a colloidal HgTe quantum dot film on a metal‐insulator‐metal plasmonic waveguide, is demonstrated. The infrared light is coupled to the plasmonic waveguide mode, significantly shrinking the device footprint and improving the light detection efficiency. This device is compatible with the standard complementary metal‐oxide semiconductor technique with promising application potential.