Intricate interactions between light and matter form the foundation of photonics innovation. This study presents a light-induced self-adaptive growth strategy for engineering multiscale ordered photonic crystal structures in perfluorosulfonic acid ionomer films. By incorporating anthracene-functionalized quaternary ammonium salts into the polymer matrix, UV irradiation triggers anthracene photodimerization, initiating localized phase separation and directional aggregation of nanoparticles along the light propagation path. The resulting nanoparticle columns exhibit programmable vertical or tilted configurations controlled by the incident light angle, establishing a bidirectional feedback loop where evolving structures modulate light propagation to guide subsequent growth. Using patterned photomasks, angle-dependent structural colors are achieved through selective reflection governed by incomplete photonic bandgaps. Furthermore, anisotropic PC architectures enable tunable light scattering and programmable grating devices, demonstrating potential applications in functional optical materials and LED displays. This fabrication strategy overcomes the static limitations of conventional photonic crystals, providing a versatile platform for creating programmable photonic architectures.
Zhou et al. (Wed,) studied this question.