2025/12/09 by Peake, Rebecca, Truyens, Zoé, Mol, Jan +4
Engineering · Materials Science · Physics and Astronomy · #Covalent Organic Framework Applications #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Surface Chemistry and Catalysis #Topological Materials and Phenomena
paper · doi:10.48550/arxiv.2512.08680
openalex publication_date 2025/12/09 · openalex created_date 2025/12/11 · openalex updated_date 2026/07/28
The tunability of covalent organic frameworks (COFs) opens opportunities to engineer topological electronic phases, including topological insulators (TIs) and higher-order topological insulators (HOTIs)--materials that host in-gap states localized at their edges, hinges, or corners. Here we explore how chemically feasible perturbations can drive triazine-based COFs (CTFs) into topological regimes. Using a tight-binding model on the Honeycomb lattice inspired by the frontier electronic states of CTFs, we show that introducing an effective uniaxial strain--implemented as a modulation of electron hopping on a subset of bonds--can generate a series of distinct topological band structures. This effect can be realized in practice through chemical substitution of linkers along the strained bonds. First-principles calculations demonstrate that replacing biphenyl with pyrene linkers drives a CTF to the brink of a HOTI phase, suggesting a viable route toward topological band-structure engineering in COFs.