Phase-Separated Nanophotonic Structures by Inkjet Printing

Abstract

The spontaneous phase separation of two or more polymers is a thermodynamic process that can take place in both biological and synthetic materials and which results in the structuring of the matter from the micro-to the nanoscale. For photonic applications, it allows forming quasi-periodic or disordered assemblies of light scatterers at high throughput and low cost. The wet process methods currently used to fabricate phase-separated nanostructures (PSNs) limit the design possibilities, which in turn hinders the deployment of PSNs in commercialized products. To tackle this shortcoming, we introduce a versatile and industrially scalable deposition method based on the inkjet printing of a polymer blend, leading to PSNs with a feature size that is tuned from a few micrometers down to sub-100 nm. Consequently, PSNs can be rapidly processed into the desired macroscopic design. We demonstrate that these printed PSNs can improve light management in manifold photonic applications, exemplified here by exploiting them as a light extraction layer and a metasurface for light-emitting devices and point-of-care biosensors, respectively.

Light in correlated disordered media

“…A recent work shows that stealthy hyperuniform structures can lead to even higher overall absorption efficiency (integrated over a spectrum of interest) compared to short-range correlated and periodic media (Liu et al, 2018). Finally, let us point out that the coupling process between free space and thin-film layers is very relevant also in the optimization of light extraction from light-emitting devices like organic LEDs (Gomard et al, 2016), where correlated disordered photonic structures could be realized on large scales, for instance, by inkjet-printing of polymer blends (Donie et al, 2021).…”

A Self‐Assembly Method for Tunable and Scalable Nano‐Stamps: A Versatile Approach for Imprinting Nanostructures

“…The attractiveness of SA for NIL‐based devices (see Table S1, Supporting Information) results from its capacity to generate easily tunable quasi‐periodic patterns to aperiodic, disordered ones with unique properties at high throughput and low‐cost. [ 27–29 ] Its benefits are therefore well aligned with those provided by NIL. However, the conventional SA is commonly based on polymer materials that exhibit low glass transition temperatures.…”

“…By tuning the polymer blend ink formulation, the PSN-based imprinting stamps may also be prepared using inkjet printing. [29,56] This approach allows the PSN to be rapidly processed into the desired macroscopic design. [29] Moreover, the developed nano-stamps that feature structural disorder are very attractive to design efficient light management patterns for large area optoelectronic devices where a cost effective method for patterning is needed.…”

“…[29,56] This approach allows the PSN to be rapidly processed into the desired macroscopic design. [29] Moreover, the developed nano-stamps that feature structural disorder are very attractive to design efficient light management patterns for large area optoelectronic devices where a cost effective method for patterning is needed. [27,[57][58][59] The two highly relevant applications are solar cells and displays.…”

Efficient light-trapping in ultrathin GaAs solar cells using quasi-random photonic crystals

“…Quasi-random photonic crystals (QR-PCs) have been proposed on passive substrates and fabricated using electron beam lithography [25,26], and using wrinkle lithography combined with reactive ion etching [27]. Another option is to use polymer blends (PBs) to create the quasi-random pattern [28][29][30][31][32]. The pattern is created by mixing two immiscible polymers in a common solvent.…”