Printing of 3D photonic crystals in titania with complete bandgap across the visible spectrum

Printing of 3D photonic crystals in titania with complete bandgap across the visible spectrum

Nature Nanotechnology

10.1038/s41565-024-01780-5

http://dx.doi.org/10.1038/s41565-024-01780-5

Wang Zhang, Jiakang Min, Hao Wang, Hongtao Wang, Xue Liang Li, Son Tung Ha, Biao Zhang, Cheng-Feng Pan, Hao Li, Hailong Liu, Hui Yin, Xiaolong Yang, Siqi Liu, Xiaodong Xu, Chaobin He, Hui Ying Yang, Joel K. W. Yang

titania, 3D printing, Color printing

09 September 2024

Zhang, W., Min, J., Wang, H., Wang, H., Li, X. L., Ha, S. T., Zhang, B., Pan, C.-F., Li, H., Liu, H., Yin, H., Yang, X., Liu, S., Xu, X., He, C., Yang, H. Y., & Yang, J. K. W. (2024). Printing of 3D photonic crystals in titania with complete bandgap across the visible spectrum. Nature Nanotechnology. https://doi.org/10.1038/s41565-024-01780-5

A photonic bandgap is a range of wavelengths wherein light is forbidden from entering a photonic crystal, similar to the electronic bandgap in semiconductors. Fabricating photonic crystals with a complete photonic bandgap in the visible spectrum presents at least two important challenges: achieving a material refractive index > ~2 and a three-dimensional patterning resolution better than ~280 nm (lattice constant of 400 nm). Here we show an approach to overcome such limitations using additive manufacturing, thus realizing high-quality, high-refractive index photonic crystals with size-tunable bandgaps across the visible spectrum. We develop a titanium ion-doped resin (Ti-Nano) for high-resolution printing by two-photon polymerization lithography. After printing, the structures are heat-treated in air to induce lattice shrinkage and produce titania nanostructures. We attain three-dimensional photonic crystals with patterning resolution as high as 180 nm and refractive index of 2.4–2.6. Optical characterization reveals ~100% reflectance within the photonic crystal bandgap in the visible range. Finally, we show capabilities in defining local defects and demonstrate proof-of-principle applications in spectrally selective perfect reflectors and chiral light discriminators.

Publisher Copyright

This research / project is supported by the National Research Foundation - NRF-Investigatorship
Grant Reference no. : NRF-NRFI06-2020-0005

This research / project is supported by the National Research Foundation - Competitive Research Programme
Grant Reference no. : NRF-CRP20-2017-0004

This research / project is supported by the Agency for Science, Technology and Research - MTC-Programmatic Funds
Grant Reference no. : M21J9b0085

This research / project is supported by the Agency for Science, Technology and Research - A*STAR Career Development Fund
Grant Reference no. : 222D800032

For publisher's version, refer here: https://www.nature.com/articles/s41565-024-01780-5

https://oar.a-star.edu.sg/communities-collections/articles/20949

1748-3387
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Institute of Materials Research and Engineering