Interfacial Charge-Transfer Excitonic Insulator in a Two-Dimensional Organic–Inorganic Superlattice

• DOI: 10.1021/jacs.4c06216
• Publication Date: 2024-07-18T08:52:35Z
• Authors: Yang Liu; Haifeng Lv; Yuqiao Guo; Hongen Zhu; Zhengmin Shang; Yingcheng Zhao; Yue Lin; Xiaolin Tai; Ziyang Guo; Xuefeng Cui; Jiyin Zhao; Bingkai Yuan; Yi Liu; Guobin Zhang; Zhe Sun; Xiaojun Wu; Yi Xie; Changzheng Wu

Excitonic insulators are long-sought-after quantum materials predicted to spontaneously open a gap by the Bose condensation of bound electron-hole pairs, namely, excitons, in their ground state. Since theoretical conjecture, extensive efforts have been devoted pursuing excitonic insulator platforms for exploring macroscopic phenomena real materials. Reliable evidence character has obtained layered chalcogenides as promising candidates. However, owing interference intrinsic lattice instabilities, it is still debatable whether those features, such charge density wave and opening, primarily driven effect or transition. Herein, we develop an intercalation chemistry strategy obtaining novel charge-transfer organic-inorganic superlattice interfaces that serves ideal platform decouple from effect. In this system, observe narrow gap, formation without periodic distortion, metal-insulator transition, providing visualized exciton occurring thermal equilibrium. Our findings identify self-assembly new developing insulators.