揭示金属酸基合二维共价有机框架中的电子特性
Mingchao Wang1, Marco Ballabio2, Mao Wang
1Center for Advancing Electronics Dresden (cfaed) and Department of Chemistry and Food Chemistry , Technische Universität Dresden , Mommsenstrasse 4 , 01062 Dresden , Germany.
Journal of the American Chemical Society
|September 27, 2019
概括
新的二维共价有机框架 (2D COF) 对电子有希望. 研究人员描述了基于Zn和Cu-phthalocyanine的2DCOF,发现了p型半导体特性和异型电荷传输,这对于传感应用至关重要.
科学领域:
- 材料科学
- 有机电子
- 半导体物理
背景情况:
- 两维共价有机框架 (2D COF) 是具有光电子和化学反射传感潜力的先进电活性材料.
- 了解 π 结合 2D COF 的结构-属性关系,特别是导电性,对于它们的应用至关重要.
- 基于氨酸的材料具有与能源和传感技术相关的独特电子和光学特性.
研究的目的:
- 综合并全面描述包含Zn和Cu-phthalocyanine单元的新型二维COF的电子特性.
- 调查中心金属原子 (Zn与Cu) 对这些二维COF中的导电性和电荷传输机制的影响.
- 通过实验和理论方法的结合,阐明电荷载体的动态,包括移动性,密度,散射和有效质量.
主要方法:
- 通过金属酸 (M = Zn,Cu) 和烯衍生物的凝结合成多晶层2DCOF.
- 包括霍尔效应测量 (DC极限) 在内的电特性,以确定导电性,电荷载体密度和移动性.
- 太赫兹 (THz) 光谱 (交流极限) 以探测更高频率的电荷载体动态.
- 密度函数理论 (DFT) 计算以补充实验发现和理解电子结构.
主要成果:
- 合成的2DCOF是p型半导体,带间距约为1.2 eV.
- 在直流极限中观察到与装置相关的电荷载体移动性高达5cm2/(Vs),受粒边界效应限制.
- 从Cu到Zn的金属中心变化对导电率 (~5 × 10−7 S/cm),载体密度 (~10−12 cm),散射率 (~3 × 10−13 s−1) 和有效质量 (~2.3 m) 的影响微乎其微.
- 发现载荷运输是异构的,与飞机外的移动性相比,飞机内移动性明显较低.
结论:
- 该研究提供了基于氨酸的新型2DCOF的详细电子特征,确定了它们作为p型半导体的潜力.
- 这些发现强调了金属中心 (Zn或Cu) 的选择对这些特定的二维COF的散装电子特性的影响很小.
- 观察到的异构电荷传输具有有限的平面移动性,是基于这些材料设计未来电子和传感器件的关键特征.
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