Plasmonic Color Printing via Bottom-Up Laser-Induced Photomodification Process

Abstract

Plasmonic color printing has received significant attention owing to its advantages such as nonfading and nontoxic color expression, without necessitating the use of chemical dyes. Recently, color generation from laser-induced plasmonic nanostructures has been extensively explored because of its simplicity, cost-effectiveness, and large-scale processability. However, these methods usually utilize a top-down method that causes unexpected background colors. Here, we proposed a novel method of plasmonic color printing via a bottom-up type laser-induced photomodification process. In the proposed method, selective silver nanoparticles (Ag NPs) structure could be fabricated on a transparent substrate through a unique organometallic solution-based laser patterning process. A set of color palettes was formed on the basis of different processing parameters such as laser fluence, scanning speed, and baking time. This color change was verified by finite-difference time-domain (FDTD) simulations via monitoring the spectral peak shift of the localized surface plasmon resonance (LSPR) at Ag NPs. It was also confirmed that the colors can be fabricated at a relatively high scanning speed (≥10 mm/s) on a large substrate (>300 mm2). Since semitransparent color images can be patterned on various transparent substrates, this process will broaden the application range of laser-induced plasmonic color generation.

Structural Color Generation on Transparent and Flexible Substrates by Nanosecond Laser Induced Periodic Surface Structures

“…The Gaussian laser fluence (φ) was calculated using equation (1) [ 25 ] and the laser fluence was calculated under defocus conditions and details can be found in previous work. [ 26 ] $$\[ \begin{array}{*{20}{c}}{\varphi \; = \frac{{2E}}{{\pi \omega _0^2}}}\end{array} \]$$where, E is the laser pulse energy and ω 0 is the beam waist radius (defocus condition). The real‐time temperature changes during laser patterning of thin films were measured using an IR camera (A35, FLIR Systems, Sweden) with 60 frames per second.…”

“…The Gaussian laser fluence (ϕ) was calculated using equation (1) [25] and the laser fluence was calculated under defocus conditions and details can be found in previous work. [26]…”

Photothermal Nanomaterials: A Powerful Light-to-Heat Converter

“…Interestingly, the photothermal reshaping of plasmonic nanostructures by laser pulses can also be realized below the melting point of a bulk metal, as explained by a surface-diffusion model. ,, Besides the laser power, adjusting the laser wavelength and polarization also provides degrees of freedom to control the structural morphologies and resultant color pixels. − Two orthogonal arms of anisotropic plasmonic nanostructures can be separately reshaped by lasers with their polarization along different directions, achieving multiplexed pixels . Instead of writing on the 2D surfaces of different materials, − the structural color prints can alternatively be prepared inside 3D matrices. − The laser printing of plasmonic colors inside transparent Au-nanodisk-embedded polymeric matrices has been demonstrated (Figure c) . The position of the focused laser spot can access a 3D space in different depths inside the polymer with uniformly distributed circular Au nanodisks, creating multiple layers of color patterns inside a single piece of matrix.…”

Femtosecond-laser nanostructuring of silicon thin films for optical information encryption

“…For example, grating-type surface structures with angle-dependent optical response can be produced by direct fs-laser processing of various materials for optical encryption and fabrication of hidden images. [13][14][15] Similarly, the utility of fs laser processing has recently been proven for structural coloring through creation of randomly or periodically arranged plasmonic nanostructures, 16,17 fabrication of hidden labels emitting in the visible or IR range 18 and optical encryption of information based on birefringence. 19 Here, nJ-energy fs-laser pulses were applied to create security labels made of hemispherical amorphous silicon nanoparticles (α-Si NP).…”