Self-assembled, chiral nanocomposites for photonic applications

Speaker: Prof. UW dr hab. Wiktor Lewandowski

Affiliation: Faculty of Chemistry, University of Warsaw

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Abstract: Thin films exhibiting chiroptical properties hold great
potential for emerging photonic technologies relying on the emission or
detection of circularly polarized light. However, further efforts to
enhance, tune, and actively regulate thin films’ chiroptical activity
are required to fully realize their potential. Recently, we addressed
these challenges by introducing a liquid crystal-assisted method for
fabricating chiroptical thin films [1].

The developed method relies on LCs forming morphologically chiral
structures, such as helical nanofibers, to guide the assembly of
nanoparticles. We have shown that this methodology is universal to Au
nanoparticles of different sizes and shapes, Au nanoclusters, perovskite
nanocrystals, and other nanoinclusions [2, 3].

Notably, these chiral assemblies exhibit high dissymmetry factors
(g-factor on the order of 0.2), which we have proven originates from the
additive molecular and supramolecular chirality [4]. Moreover, the
materials we achieve can respond to thermal and light stimuli [5]. We
recently used these materials to fabricate thin films with a pixelated
structure, where each pixel exhibits on-demand controlled plasmonic and
electronic handedness [6].

Overall, our approach toward achieving chiral nanomaterials offers
advantages for communication, display, and anticounterfeiting
technologies.

[1] Advanced Materials 32, 1904581 (2020).
[2] Advanced Functional Materials 32, 2111280 (2022).
[3] ACS Nano 16, 18472-18482 (2022).
[4] ACS Photonics 11, 4, 1771–1779 (2024).
[5] ACS Nano 17, 6, 5548-5560 (2023).
[6] Advanced Materials 36, 2310197 (2024).

Chairman: Bartlomiej Graczykowski