Simulation of Monolithically Integrated Meta-Lens with Colloidal Quantum Dot Infrared Detectors for Enhanced Absorption

Abstract

Colloidal quantum dots (CQDs) have been intensively investigated over the past decades in various fields for both light detection and emission applications due to their advantages like low cost, large-scale production, and tunable spectral absorption. However, current infrared CQD detectors still suffer from one common problem, which is the low absorption rate limited by CQD film thickness. Here, we report a simulation study of CQD infrared detectors with monolithically integrated meta-lenses as light concentrators. The design of the meta-lens for 4 μm infrared was investigated and simulation results show that light intensity in the focused region is ~20 times higher. Full device stacks were also simulated, and results show that, with a meta-lens, high absorption of 80% can be achieved even when the electric area of the CQD detectors was decreased by a factor of 64. With higher absorption and a smaller detector area, the employment of meta-lenses as optical concentrators could possibly improve the detectivity by a factor of 32. Therefore, we believe that integration of CQD infrared detectors with meta-lenses could serve as a promising route towards high performance infrared optoelectronics.

Band-engineered dual-band visible and short-wave infrared photodetector with metal chalcogenide colloidal quantum dots

“…[52][53][54][55][56][57][58][59][60] The refractive index of the CQD film is 2.3 + 0.1i. 61,62 Besides, the energy bandgap of ZnO is 3.3 eV in the simulation. [52][53][54][55][56] Layers of p-type Ag 2 Te and n-type ZnO are introduced at the top of HgTe and at the interface between HgTe and CdTe, respectively.…”

Bias Reconfigurable Photoresponse of an Infrared Nanocrystal Film Integrated into a Coupled Fabry-Perot Resonator

“…Various photonic concepts have been proposed to enhance the absorption efficiency and shape the absorption spectrum: flat lenses, Fabry-Perot resonators, magnification of the field by metal tips, plasmonic cavities, ,, Bragg mirrors, guided-mode resonators, , metal–insulator–metal cavities, metasurfaces, epsilon-near-zero resonances, , Helmholtz resonators, and combinations of these. , The first purpose of these photonic structures is to modify either the magnitude or the linewidth of the absorption. However, it has also been proposed that photonic structures can actively modify the shape of the spectrum , after the device fabrication.…”

Helmholtz Resonator Applied to Nanocrystal-Based Infrared Sensing

“…This has raised the need to couple the absorbing/emitting layer to a photonic structure 12 to shape the absorption 13 or enhance its magnitude. 14−16 Several concepts of photonic structures have been explored, including surface plasmonics, 17 a metal−insulator−metal cavity, 18 optical lens, 19 Fabry−Perot cavity, 20 plasmonic cavity, 21,22 guided-mode resonator, 23−25 epsilon-near-zero resonator, 26,27 electromagnetically induced absorber, 28 distributed Bragg reflector 13,29 and even the combination of some of them. 14,30 In this paper, we explore the design of an optical resonator equivalent to a Helmholtz resonator initially developed for acoustics, 31 see Figure 1a.…”

“…However, in most devices, the light-matter interaction is dictated by the electronic structure of the material itself. This has raised the need to couple the absorbing/emitting layer to a photonic structure to shape the absorption or enhance its magnitude. − Several concepts of photonic structures have been explored, including surface plasmonics, a metal–insulator–metal cavity, optical lens, Fabry−Perot cavity, plasmonic cavity, , guided-mode resonator, − epsilon-near-zero resonator, , electromagnetically induced absorber, distributed Bragg reflector , and even the combination of some of them. , …”