Themed issue: the chemistry of photonic crystals and metamaterials

Yadong Yin

Jianping Ge

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Photonic crystals and their composite materials have attracted tremendous interest in the past decade due to their ability to effectively manipulate light. Coinciding with the rapid development of the synthesis and fabrication techniques, a great number of intriguing photonic applications have been demonstrated, including robust structural color coatings on industrial products, colorimetric sensors for detecting physical, chemical, and biological changes, antiglare displays and printing, security devices such as color fingerprints and anticounterfeiting labels, and solar energy enrichment systems. The progress made with photonic crystals has also led to the growth of the new highly relevant field of metamaterials. There is no doubt that in the near future we will witness the positive influence of these novel materials upon our daily life.

Looking back on the history of photonic crystal development, one can see the close integration of efforts from various fields, including materials science, chemistry, physics, and engineering. Such development is also accompanied by parallel endeavors in exploring new designs for materials and structures and finding niche applications. As a group of techniques promising easier access to more materials and rapid and cost-effective fabrication, self-assembly approaches have gained particular attention, especially from the chemistry community. Unsatisfied with the early preparation methods based on slow solvent evaporation or precipitation, researchers have proposed a great number of new fabrication techniques with improved efficiency and reproducibility, including, as shown in the examples in this themed issue, spin coating, inkjet printing, block copolymer assembly, liquid flow directed assembly, and electric/magnetic field manipulation. Meanwhile, as required by the practical applications of these materials, research interests have gradually shifted from the preparation of fixed photonic crystals to the fabrication of responsive photonic crystals whose structures and optical output can be rapidly and reversibly tuned by external stimuli. Furthermore, research enthusiasm for crystalline photonic crystals has been extended to so-called “amorphous photonic crystals”, as inspired by the fact that many living creatures exhibit bright structural colors based on less ordered structures. We anticipate that the next few years will be very important for pushing the research on photonic crystal materials towards practical applications.

The fast development in the fabrication and use of photonic structures in recent years has motivated us to initiate a themed issue focusing on the chemistry of photonic crystals and metamaterials. In this themed issue, many experts in the relevant fields discuss several effective fabrication techniques to produce two- and three-dimensional colloidal photonic crystals. This themed issue also introduces recent advances in the development of electromagnetic tunable photonic crystals, photonic based ink-jet printing, photonic sensing and detection, and lasing in photonic crystals. Although it is not possible to include all the topics in this fast developing field, we hope this issue can provide the reader with an overview of the recent progress achieved in this exciting area and the potential broader impact of the studies in photonic crystals.

We want to thank all the contributing groups for their excellent works. We also want to thank the editorial staff of Journal of Materials Chemistry C for their help with organizing this issue. We hope the photonic crystal community will enjoy reading about the interesting topics presented here, which may inspire further development in this exciting research field.

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