Light Absorber With Random Dielectric Protrusions For Broadband Infrared Absorption
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Solution Overview
Problem
Conventional light absorbers utilizing surface plasmon resonances have limited absorption bandwidth, insufficient for applications requiring efficient light absorption across a wide wavelength range, particularly in the visible and near-infrared regions.
Innovation Solution
A light absorber with a metal-dielectric-metal (MIM) structure featuring dielectric protrusions and a conductive thin film on the protrusions, along with a separate conductive thick film, is designed to enhance absorption by introducing randomness in the dielectric protrusion arrangement, broadening the absorption bandwidth and reducing incident angle dependency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional surface plasmon resonance structures are used, then absorption in a specific wavelength range is enhanced, but the absorption bandwidth is limited
Solution Approach 1:
The patent divides the surface into multiple regions with different dielectric constant distributions (first region with first distribution, second region with second distribution). Each region contributes to different aspects of the absorption spectrum, and their combination achieves broadband absorption across 400-5000 nm, resolving the contradiction between enhanced absorption at specific wavelengths and limited bandwidth.
Solution Approach 2:
The patent applies different dielectric constant distributions in different spatial regions of the structure. The first region has a specific distribution pattern optimized for certain wavelengths, while the second region has a different distribution pattern for other wavelengths. This local differentiation enables the structure to maintain high absorption efficiency across a broad spectrum simultaneously.
2Use of energy by moving object
If regular light absorbers are used, then absorption in certain wavelength ranges is achieved, but incident angle dependency is significant
Solution Approach 1:
The patent introduces asymmetric dielectric constant distributions in the surface regions, which creates multiple scattering paths and resonance modes that are less sensitive to incident angle. This asymmetry in the dielectric distribution helps maintain consistent absorption performance across different angles of light incidence, reducing the typical angle dependency of plasmonic absorbers.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves high absorption across a wide wavelength range from 400 nm to 5000 nm with minimal incident angle dependency, suitable for various applications including bolometers, solar thermal power generation, and radiative cooling.
Implementation Method 1
absorption by surface plasmons is adopted for organic solar cells (plasmonic solar cells), as a wide wavelength range are utilized
Data Source
AI summary
In order to realize a light absorber wherein the wavelengths absorbed can be adjusted, an embodiment of the present invention provides a light absorber 100 provided with a group of dielectric protrusions 102, a conductive thin film 104, and a conductive thick film 108. The group of dielectric protrusions has each dielectric protrusion protruding at a random position on a dielectric surface. A dielectric thin film is disposed on or above at least part of the surface of the dielectric protrusions and on or above at least part of the dielectric surface where the dielectric protrusions are not present; and the dielectric thick film spreads out along the dielectric surface and being kept separate from the dielectric thin film. The group of dielectric protrusions can be provided by disposition of dielectric particles in an in-plane random arrangement on the surface. The present invention also provides a bolometer, an infrared light absorber, a solar thermal power generating device, and a radiative cooling film adopting the light absorber above as well as a method for manufacturing the light absorber.