Wakizaka Masanori, Ishiguro Keisuke, Yoshida Takefumi, Iguchi Hiroaki, Tsumuraya Takao, Ito Hiroshi, Yamashita Masahiro, Takaishi Shinya
Department of Applied Chemistry and Bioscience, Faculty of Science and Technology, Chitose Institute of Science and Technology, 758-65 Bibi, Chitose 066-8655, Japan.
Department of Applied Physics, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan.
ACS Appl Mater Interfaces. 2025 Mar 5;17(9):14322-14328. doi: 10.1021/acsami.4c22128. Epub 2025 Feb 20.
The fabrication of heterostructures from low-dimensional materials is very challenging, particularly the creation of low-dimensional heterojunctions that can be characterized at an atomic resolution. In a previous work, a two-dimensional (2D) heterostructure made from halogen-bridged metal complexes (MX-Chains), [Ni(chxn)Br]Br (chxn = 1,2-diaminocyclohexane) and [Pd(chxn)Br]Br, has been synthesized, and the nature of the electronically 1D heterojunction at an atomic resolution was revealed. In the work reported here, we have successfully fabricated double core-shell crystals (Ni-Pd-Ni) from these MX-Chains, using a stepwise electrochemical epitaxial method. Upon cleavage of the heterostructure along the van der Waals layers, a double heterojunction surface is observed. The MX-Chains are aligned in the heterostructure and exhibit anisotropic optical properties based on their 1D electronic systems, as measured using UV-vis-NIR polarized reflectance microscopy. Current-voltage curves at different temperatures are recorded using three probes attached to different areas of the heterostructure and reveal the presence of ohmic conduction through the double 1D heterojunctions. The ohmic contact between the two types of MX-Chains arises from the atomic-scale connection of the MX-Chains at the heterojunction. This work represents the first example of a molecule-based heterostructure that has electronic conductivity and demonstrates electrical conduction through a 1D heterojunction.
由低维材料制备异质结构极具挑战性，尤其是创建能够在原子分辨率下进行表征的低维异质结。在先前的一项工作中，已合成了一种由卤素桥连金属配合物（MX链）、[Ni(chxn)Br]Br（chxn = 1,2 - 二氨基环己烷）和[Pd(chxn)Br]Br制成的二维（2D）异质结构，并揭示了原子分辨率下电子一维异质结的本质。在本文报道的工作中，我们使用逐步电化学外延法成功地从这些MX链制备出了双核壳晶体（Ni - Pd - Ni）。沿范德华层劈开异质结构时，会观察到双异质结表面。MX链在异质结构中排列，并基于其一维电子系统表现出各向异性光学性质，这是使用紫外 - 可见 - 近红外偏振反射显微镜测量得出的。使用连接到异质结构不同区域的三个探针记录不同温度下的电流 - 电压曲线，结果表明通过双一维异质结存在欧姆传导。两种类型的MX链之间的欧姆接触源于异质结处MX链的原子尺度连接。这项工作代表了具有电子导电性并展示通过一维异质结导电的基于分子的异质结构的首个实例。
