Lu Weiqun, Lee Hyungseok, Cha Joonil, Zhang Jian, Chung In
School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea.
Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea.
Angew Chem Int Ed Engl. 2023 Apr 17;62(17):e202219344. doi: 10.1002/anie.202219344. Epub 2023 Mar 20.
The core task for Mott insulators includes how rigid distributions of electrons evolve and how these induce exotic physical phenomena. However, it is highly challenging to chemically dope Mott insulators to tune properties. Herein, we report how to tailor electronic structures of the honeycomb Mott insulator RuCl employing a facile and reversible single-crystal to single-crystal intercalation process. The resulting product (NH ) RuCl ⋅1.5 H O forms a new hybrid superlattice of alternating RuCl monolayers with NH and H O molecules. Its manipulated electronic structure markedly shrinks the Mott-Hubbard gap from 1.2 to 0.7 eV. Its electrical conductivity increases by more than 10 folds. This arises from concurrently enhanced carrier concentration and mobility in contrary to the general physics rule of their inverse proportionality. We show topotactic and topochemical intercalation chemistry to control Mott insulators, escalating the prospect of discovering exotic physical phenomena.
莫特绝缘体的核心任务包括电子的刚性分布如何演变以及这些分布如何引发奇异的物理现象。然而，通过化学掺杂来调控莫特绝缘体的性质极具挑战性。在此，我们报告了如何利用一种简便且可逆的单晶到单晶插层过程来定制蜂窝状莫特绝缘体RuCl的电子结构。所得产物(NH ) RuCl ⋅1.5 H O形成了由交替的RuCl单层与NH 和H O分子构成的新型混合超晶格。其经调控的电子结构显著地将莫特 - 哈伯德能隙从1.2 eV缩小至0.7 eV。其电导率增加了10倍以上。这是由于载流子浓度和迁移率同时增强，这与它们成反比的一般物理规律相反。我们展示了用于控制莫特绝缘体的拓扑化学插层化学，提升了发现奇异物理现象的前景。
