Plasmonic Colors: Toward Mass Production of Metasurfaces

absorption of light. It is, however, possible to engineer artificial materials that are extremely thin and can absorb nearly 100% of the incident light. The most common approach to achieving near perfect absorption (NPA) of light consists of "blocking" the possibility of transmission by, for example, using a reflective surface. Under these circumstances, the amount of light absorbed is controlled by the reflectance of the material, since, in these cases, the absorption is given by A = 1 − | r | 2 . Clearly, high absorption can be obtained when there is vanishing reflectance (r = 0), which takes place under conditions of optical impedance matching. [4] In the following section, we discuss physical interpretations and mechanisms that have been employed for achieving near complete absorption of light using metallic nanostructures, including metasurfaces, as the absorptive element. This is followed by an overview of the applications of near-perfect absorption in fields such as chemical sensing, optoelectronics and photocatalysis. This review ends with an outlook. We note that near-perfect absorption can be achieved with a wide range of materials, for which excellent review papers have been previously published. [5][6][7] The Physics of Perfect Absorption Thin Film Perfect Absorbers: InterferenceAs an introduction, we first review simple thin film approaches to NPA since these play a fundamental role in understanding the underlying physics. Optical thin-film coatings are essential in optical systems today and the simplest example of a thin-film absorber consists of a stack of an optically thin metal film, a thin dielectric film and a highly reflective metallic film. Thin film coatings are widely used as anti-and high-reflection coatings, beamsplitters, and wavelength filters on lenses, windows, displays, [8] and absorbers for efficiency enhancements in photovoltaic cells, [9] as well light emitting diodes (LED) and photodetectors. [10] Their characteristics, design, and fabrication have been studied for over a century and are well-known. [4] In the next section, we will further discuss thin film absorbers where one layer is textured on the nanoscale, but thin-film systems are particularly useful as optical absorbers exhibiting distinct advantages over nanostructured optical metasurfaces. While textured surfaces require an additional level of processing, potentially requiring complex, top-down nanofabrication techniques, [11][12][13] Near-complete absorption of light has the potential to underpin advances in photodetection, advanced chemistry, coloration of materials, and energy. This review paper reports recent progress on the development of metasurfaces and thin film structures that produce strong absorption bands in the visible and longer wavelength regions of the electromagnetic spectrum, due in part to the excitation of plasmonic resonances. Proof-of-concept demonstrations are discussed for applications of these in chemical sensing, the generation of structural color, the creation of optoelectronic devices, and p...

Section: Applicationsmentioning

confidence: 99%

Plasmonic Near‐Complete Optical Absorption and Its Applications

Wesemann

Panchenko

et al. 2019

“…[26,27] The manufacturing of plasmonic nanostructures usually involves multiple steps of nanofabrication that is of high cost and time consumption and is challenging to scale up. [28,29] A robust method is therefore highly desired for the fabrication of plasmonic color patterns in 3D matrices.…”

Section: Plasmonic Color Laser Printing Inside Transparent Gold Nanodmentioning

confidence: 99%

“…In addition, metal nanostructures prepared by the aforementioned top‐down fabrication techniques usually suffer from large plasmon damping caused by their polycrystalline nature and the use of adhesive layers . The manufacturing of plasmonic nanostructures usually involves multiple steps of nanofabrication that is of high cost and time consumption and is challenging to scale up . A robust method is therefore highly desired for the fabrication of plasmonic color patterns in 3D matrices.…”

mentioning

confidence: 99%

Plasmonic Color Laser Printing inside Transparent Gold Nanodisk‐Embedded Poly(dimethylsiloxane) Matrices

Cui

Zhu

Shao

et al. 2019

Self Cite

Plasmonic color generation from metal nanostructures has attracted intensive attention because of their excellence in achieving high spatial resolution, strong color contrast, and long‐term durability. The limited area of plasmonic patterns anchored on substrates and produced by current top‐down methods, however, severely restricts the advanced developments and potential applications in structural color display. Herein a robust method for realizing the laser printing of plasmonic colors inside transparent gold nanodisk‐embedded poly(dimethylsiloxane) matrices is presented. It is found that various colors can not only be easily generated by embedding gold nanodisks of different sizes, but also finely varied by adjusting the laser pulse intensity during printing. It is further demonstrated that multiple color layers can be laser‐printed at different depths. Stereoscopic images in the 3D matrices are laser‐printed with sizes as large as 12 × 15 mm2 and a resolution of 4600 dots per inch.

“…Structural colors arise from the interaction of light with surface structures . Fundamental optical phenomena such as interference, diffraction, scattering, and resonance are the origins of structural colors.…”

mentioning

confidence: 99%

Printing of Highly Vivid Structural Colors on Metal Substrates with a Metal‐Dielectric Double Layer

Seo

Kim

et al. 2019

of metals rapidly extend into mobile electronics, home appliances, art/decoration, and building interiors, their aesthetic functions are becoming increasingly significant. Surface decoration with sensuous colors is essential for improving the aesthetic appearance of a material. Light control at the surface of metals endows them with additional functionality beyond their traditional roles as mechanical supporters and electrical conductors. Nature emanates brilliant structural colors. The beautiful colors of bird feathers and butterfly wings may be the brightest structural colors in nature. Over the past decades, numerous artificial structures have been investigated for reproducing the structural colors of living creatures, which include nanoparticle assemblies, multiscale structures, photonic crystals, diffraction gratings, plasmonic nanostructures, and selective mirrors. [7][8][9][11][12][13][14] However, these biomimetic structures have mostly been fabricated on glass, Si, and plastic substrates. Moreover, many are impractical to apply for bulk metals due to issues with fabrication complexity, scalability, and durability. A photonic crystal (PC) is a periodic optical structure that affects the motion of photons in much the same way that crystal lattices affect electrons in solids. PC films can be fabricated by various methods. [15][16][17] Metal surfaces finished in color images or patterns are useful in a range of applications, including reflective color filters, interiors, sculpture, art, and jewellery. While PC films can produce highly saturated structural colors, they are not suitable for printing color images on metal substrates. In order to tune the produced color, the periodicity or the refractive-index variation of the PC structure should be modified. A scheme for colorizing metals should be simple and scalable and, most importantly, allow for easy color tuning. Herein, we propose a simple surface structure for producing vivid colors on stainless steel (STS) and Al, which are two of the most widely used metals.The proposed structure comprises a dielectric film inserted between a bulk metal substrate and thin metallic layer (Figure 1a). Metal-insulator-metal (MIM) thin-film stacks, which are Fabry-Perot (FP)-type resonant cavities, have been extensively investigated to realize near-perfect absorbers on opaque substrates and transmissive color filters on transparent substrates. [18][19][20][21][22] Because this MIM cavity acts as a band-stop The aesthetic functions of metals have attracted increasing attention, and their colorization is of scientific and technological significance. This study demonstrates that vivid structural colors can be produced on stainless steel and Al, which are two of the most commonly used metals. It is well known that a transparent dielectric film coated onto a substrate exhibits a rippled spectrum consisting of alternating reflectance minima and maxima due to multibeam interference, making it appear colored. However, such a film does not produce strong colors on a highly reflect...