Signatures of Band-like Charge Carrier Transport in a Three-Dimensional Fe-HHTP Metal–Organic Framework

IF 4.5 2区化学 Q2 CHEMISTRY, PHYSICAL

The Journal of Physical Chemistry Letters Pub Date : 2026-10-14 DOI:10.1021/acs.jpclett.6c03062

Md Soif Ahmed,Marina I. Schönherr,Marco Ballabio,Sandra M. Estévez,Mariela Menghini,Dana D. Medina,Enrique Cánovas

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引用次数: 0

Abstract

Abstract Metal–organic frameworks (MOFs) offer exceptional structural and chemical tunability, and the emergence of electrically conductive variants creates new opportunities for functional optoelectronic materials. Here, we investigate charge transport in a three-dimensional (3D) Fe-HHTP MOF (or Fe-CAU-42), composed of hexahydroxytriphenylene (HHTP)-based supertetrahedral units and trimeric Fe(III) oxo cluster nodes arranged in a diamond structure. Temperature dependent Van der Pauw (vdP) electrical conductivity measurements reveal an Arrhenius-type thermally activated charge transport mechanism operating in pelletized samples. Terahertz time-domain spectroscopy is used to probe the frequency-resolved complex conductivity of the Fe-HHTP pellet. The THz conductivity spectra are well-described by the Drude–Smith model, indicating the presence of mobile charge carriers with band-like dynamics subject to backscattering and localization. Temperature-dependent conductivity analysis reveals that the increase in conductivity with temperature is governed primarily by changes in carrier density rather than by changes in scattering time (and hence mobility). DC conductivities ranging from 6.54 × 10–3 S cm–1 at 300 K to 1.22 × 10–3 S cm–1 at 77 K are extracted from modeling of the THz data, in excellent agreement with van der Pauw measurements. The combined results establish a transport picture in which charge motion is dominated by localized band-like charge carriers with thermally activated carrier density, providing direct insight into carrier dynamics in conductive 3D catecholate MOFs.

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三维Fe-HHTP金属-有机骨架中带状电荷载流子输运的特征

金属有机框架（mof）提供了卓越的结构和化学可调性，导电变体的出现为功能光电材料创造了新的机会。本文研究了由六羟基三苯（HHTP）超四面体单元和三聚铁（III）氧簇节点组成的三维（3D） Fe-HHTP MOF（或Fe- cau -42）中的电荷输运。温度依赖范德保（vdP）电导率测量揭示了在球团样品中运行的阿雷尼乌斯型热激活电荷输运机制。采用太赫兹时域光谱法探测铁- hhtp球团的频率分辨复电导率。德鲁德-史密斯模型很好地描述了太赫兹电导率谱，表明存在受后向散射和局部化影响的带状动力学的移动电荷载流子。温度相关的电导率分析表明，电导率随温度的增加主要受载流子密度的变化而不是散射时间（因此迁移率）的变化所控制。从太赫兹数据建模中提取的直流电导率范围为300 K时的6.54 × 10-3 S cm-1到77 K时的1.22 × 10-3 S cm-1，与van der Pauw测量结果非常吻合。综合结果建立了一个输运图，其中电荷运动由具有热激活载流子密度的局域带状载流子主导，为导电3D儿茶酚酸mof中的载流子动力学提供了直接的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

The Journal of Physical Chemistry Letters CHEMISTRY, PHYSICAL-NANOSCIENCE & NANOTECHNOLOGY

CiteScore

9.60

自引率

7.00%

发文量

1519

审稿时长

1.6 months

期刊介绍： The Journal of Physical Chemistry (JPC) Letters is devoted to reporting new and original experimental and theoretical basic research of interest to physical chemists, biophysical chemists, chemical physicists, physicists, material scientists, and engineers. An important criterion for acceptance is that the paper reports a significant scientific advance and/or physical insight such that rapid publication is essential. Two issues of JPC Letters are published each month.