Seminar: Programming Self-Assembly for Colloidal Photonic Crystals

Abstract:
Colloidal particles in the hundreds-of-nanometres size range are attractive building blocks for photonic crystals with a complete photonic band gap in the visible [1]. However, self-assembly of colloidal photonic crystals, touted as a low-cost, scalable fabrication technique, has proved elusive [2,3]. Diamond-structured colloidal crystals – much sought-after in their cubic form for a complete photonic band gap [4,5] – continue to remain challenging targets for scalable fabrication via programmed self-assembly, even after recent breakthroughs [6,7]. In this presentation, I will demonstrate, using a variety of computer simulation techniques, how hierarchical self-assembly pathways can be programmed and medium-range order can be encoded in designer patchy particles for facile self-assembly of colloidal photonic crystals [8-14]. I will highlight how certain long-standing challenges have been addressed to push the frontiers of colloidal self-assembly, in close connection with recent advances in the synthesis of colloidal matter [15].

[1] J. D. Joannopoulos, P. R. Villeneuve and S. Fan, Nature 386, 143 (1997). [2] G. von Freymann, V. Kitaev, B. V. Lotsch and G. A. Ozin, Chem. Soc. Rev. 42, 252 (2013).
[3] Z. Cai et al., Chem. Soc. Rev. 50, 5898 (2021).
[4] K. M. Ho, C. T. Chan and C. M. Soukoulis, Phys. Rev. Lett. 65, 3152 (1990).
[5] M. Maldovan and E. L. Thomas, Nat. Mater. 3, 593 (2004).
[6] M. He et al., Nature 585, 524 (2020).
[7] G. Posnjak et al., Science 384, 781 (2024).
[8] D. Morphew, J. Shaw, C. Avins and D. Chakrabarti, ACS Nano 12, 2355 (2018).
[9] A. B. Rao et al., ACS Nano 14, 5348 (2020).
[10] A. Neophytou, V. N. Manoharan and D. Chakrabarti, ACS Nano 15, 2668 (2021).
[11] A. Neophytou, D. Chakrabarti and F. Sciortino, Proc. Natl. Acad. Sci. USA 118, e2109776118
(2021).
[12] W. Flavell, A. Neophytou, A. Demetriadou, T. Albrecht and D. Chakrabarti, Adv. Mater. 35, 2211197 (2023).
[13] A. Walker et al. Small (2026).
[14] A. Walker, C. M. Sotomayor Torres and D. Chakrabarti, Unpublished.
[15] T. Hueckel, G. M. Hocky and S. Sacanna, Nat. Rev. Mater. 6, 1053 (2021