Narrowing band gap chemically and physically: conductive dense hydrocarbon

作者：Takeshi Nakagawa, Caoshun Zhang, Kejun Bu, Philip Dalladay‐Simpson, Martina Vrankić, S. R. Bolton, Dominique Laniel, Dong Wang, Akun Liang, Hirofumi Ishii, Nozomu Hiraoka, Gastón Garbarino, Angelika D. Rosa, Qingyang Hu, Xujie Lü, Ho‐kwang Mao, Yang Ding · 发表于：Communications Materials · 年份：2025 · DOI：10.1038/s43246-025-00814-2 · 被引用次数：4 · 研究领域：High-pressure geophysics and materials、Advanced Chemical Physics Studies、Solid-state spectroscopy and crystallography

Enhancing intermolecular interactions can reduce the band gap energy of organic molecules. Consequently, certain polycyclic aromatic hydrocarbons – typically wide-band-gap insulators – may undergo insulator-to-metal transitions under simple compression. This pressure-induced electronic transition could enable the transformation of non-metallic organic materials into states exhibiting intriguing electronic properties, including high-temperature superconductivity. Here we investigate a pressure-induced transition in dicoronylene (C48H20), an insulator at ambient conditions, to a semiconducting state with a resistivity drop of three-orders-of-magnitude at 23.0 GPa. Through the complementary integration of transport property measurements with in situ UV-Visible absorption, Raman spectroscopy and synchrotron X-ray diffraction experiments, as well as first-principles studies, we propose a possible mechanism for the pressure-driven electronic structure evolution of C48H20. The discovery of an intriguing electronic transition at pressures well below the megabar observed marks a promising step towards realizing a single-component purely hydrocarbon molecular metal. Polycyclic aromatic hydrocarbons, typically wide-band-gap insulators, may transform into metals under compression, offering potential for interesting electronic properties. Here, a pressure-induced insulator-to-semiconductor transition in dicoronylene was demonstrated, achieving a resistivity drop at 23.0 GPa, and a mechani...