Integrated Plasmonic Infrared Photodetector Based on Colloidal HgTe Quantum Dots

Abstract

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.

Mercury Chalcogenide Quantum Dots: Material Perspective for Device Integration

“…The concept is to collect photons over an area that is as large as possible while reducing the electrical area as much as possible, thereby proportionately decreasing the dark current. 387 Zhu et al recently demonstrated 388 a device based on a silicon photonic waveguide with a small volume of HgTe used as an IR absorbing material. This structure shows an enhanced detectivity compared to the bare HgTe film.…”

Integration of Colloidal Quantum Dots with Photonic Structures for Optoelectronic and Optical Devices

“…designed a plasmonic–silicon hybrid waveguide system integrated with a HgTe QD active layer and demonstrated on‐chip photodetection at the guided wavelength of ≈1600 [ 87 ] and ≈2300 nm, respectively (Figure 8d ). [ 86 ] The device was fabricated on the commonly used silicon‐on‐insulator substrate, using the input and output silicon waveguide grating coupler for light guiding. The center metal–insulator–metal (MIM) waveguide structure not only functioned as a plasmonic waveguide to concentrate the propagation mode into the QD region, but also served as the electrodes of the photodetector for current conduction.…”

Infrared photoconduction at the diffusion length limit in HgTe nanocrystal arrays

“…Progresses on both material growth 2 – 6 and device design 7 transformed HgTe NCs into a versatile platform for IR optoelectronics 8 . Key developments include on-chip integration 9 , coupling to resonators to achieve strongly-absorbing devices 10 – 14 and hybridization to read out circuits to design focal plane arrays operating in the short-wave 15 , 16 and mid-wave IR 17 , 18 .…”