Modeling Cutting-Edge Organic Hyperbolic Metamaterial for Super-Resolution Imaging via First-Principles Study

Hyperbolic materials have attracted significant attention due to their unique optical properties including negative refraction^[1], nanoscale light focusing, amplified scattering^[2]. These properties enable super-resolution imaging, making hyperbolic materials highly valuable in advanced optical applications. Conventional hyperbolic metamaterials are composed of alternating metal-dielectric stacks, limiting their properties due to constraints in reducing the interlayer spacing. In contrast, recently discovered organic hyperbolic metamaterials (OHMs) overcome the limitation and exhibit excellent hyperbolic properties.^[3] Moreover, OHMs show high biocompatibility and flexibility, making them promising candidates for various optoelectronic device applications. In this study, we propose for the first time that self-assembled polymeric films consisting of donor-acceptor (D-A) conjugated polymers can facilitate low-loss multi-band hyperbolic dispersion (HD) through first-principles calculations. We explore various copolymers composed of thiophene (D) and benzothiadiazole (A) units by determining their most stable molecular crystalline structures and calculating their frequency-dependent dielectric functions to evaluate their HD performance. Additionally, we investigate electronic structures, including band structures and partial density of states, to understand the influence of bridge or spacer unit incorporation on HD properties. As a result, we discover the multi-band HDs from candidate OHMs with a new record in theoretical figure-of-merit and find that tuning the building units of polymers or adjusting the film condition can change the wavelength range exhibiting HD. The potentials of candidate OHMs are also confirmed from the calculated volumetric confinement and propagation of high-k hyperbolic polaritons using finite-difference time-domain (FDTD) simulation. Consequently, this study provides novel insights into the molecular-scale design of low-loss OHMs for the target wavelength range.<br/><br/>References:<br/>[1] Yao, Jie, <i>et al.</i>, <i>Science</i> 321.5891 <b>(2008)</b><br/>[2] Lee, Yeon Ui, <i>et al.</i>, <i>Nature communications</i> 13.1 <b>(2022)</b><br/>[3] Lee, Yeon Ui, <i>et al.</i>, <i>Advanced Materials</i> 32.28 <b>(2020)</b>