Silicon carbide as a material-based high-impedance surface for enhanced absorption within ultra-thin metallic films

Abstract

The absorption of infrared radiation within ultra-thin metallic films is technologically relevant for different thermal engineering applications and optoelectronic devices, as well as for fundamental research on sub-nanometer and atomically-thin materials. However, the maximal attainable absorption within an ultra-thin metallic film is intrinsically limited by both its geometry and material properties. Here, we demonstrate that material-based high-impedance surfaces enhance the absorptivity of the films, potentially leading to perfect absorption for optimal resistive layers, and a fourfold enhancement for films at deep nanometer scales. Moreover, material-based high-impedance surfaces do not suffer from spatial dispersion and the geometrical restrictions of their metamaterial counterparts. We provide a proof-of-concept experimental demonstration by using titanium nanofilms on top of a silicon carbide substrate.

Application of ZnO Semiconductor Nanomaterial Ink in Packaging and Printing Design

“…Nanoparticles also require other synthetic methods to prepare them, such as electrochemical deposition, electroless plating, chemical deposition, sol-gel, etc. [14].…”

Spectrally stable thermal emitters enabled by material-based high-impedance surfaces

“…48 By contrast, material-based HISs take advantage of the material properties of a dispersive medium to implement a HISs without the need of fabricating a metamaterial construct. 49,50 Here, we numerically and experimentally demonstrate that material-based HISs exhibit an unusually stable absorptivity/emissivity spectrum, characterized by a narrow band peak, whose frequency position is independent of the geometry of the metallic lm, the angle of observation and polarization.…”

Tailoring Infrared Absorption and Thermal Emission with Ultrathin Film Interferences in Epsilon‐Near‐Zero Media

“…Introduction of loss in the film modifies the phases as shown by solid lines in Figure 4a. The plot demonstrates that in the ITER regime, the reflection phase at the top interface plays a dominant role in determining resonant interferences, which require ϕ 12 ¼ ϕ d , in contrast to those in Fabry-Perot resonances (which is determined by propagation phase in the film) and the previously investigated ultrathin film interferences [11][12][13][14][15][16][17][18][19][20] dominated by reflection phase at the bottom interface. Figure 4b plots the variation in magnitudes of r 12 and e 2iδ for real and lossless ENZ.…”

“…Such homogeneous ultrathin films are attractive for applications in coloring, filtering, absorption enhancement in photovoltaic applications, infrared absorbers and emitters, and in reconfigurable flat optics. [11][12][13][14][15][16][17][18][19][20] Epsilon-near-zero (ENZ) materials are one such class of thin film materials that have gained much interest in recent times. [21,22] The real part of permittivity (ε 0 ) of ENZ materials becomes zero at the zero-epsilon wavelength (λ ZE ), such that ε 0 is positive (negative) at shorter (longer) wavelengths.…”