Open AccessOutstanding Charge Mobility by Band Transport in Two-Dimensional Semiconducting Covalent Organic Frameworks
Author(s) -
Shuai Fu,
Enquan Jin,
Hiroki Hanayama,
Wenhao Zheng,
Heng Zhang,
Lucia Di Virgilio,
Matthew A. Addicoat,
Markus Mezger,
Akimitsu Narita,
Mischa Bonn,
Kläus Müllen,
Hai I. Wang
Publication year - 2022
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.2c02408
Subject(s) - organic electronics , chemistry , charge carrier , thin film , chemical physics , electron mobility , nanotechnology , photoconductivity , covalent bond , materials science , optoelectronics , organic chemistry , physics , transistor , quantum mechanics , voltage
Two-dimensional covalent organic frameworks (2D COFs) represent a family of crystalline porous polymers with a long-range order and well-defined open nanochannels that hold great promise for electronics, catalysis, sensing, and energy storage. To date, the development of highly conductive 2D COFs has remained challenging due to the finite π-conjugation along the 2D lattice and charge localization at grain boundaries. Furthermore, the charge transport mechanism within the crystalline framework remains elusive. Here, time- and frequency-resolved terahertz spectroscopy reveals intrinsically Drude-type band transport of charge carriers in semiconducting 2D COF thin films condensed by 1,3,5-tris(4-aminophenyl)benzene (TPB) and 1,3,5-triformylbenzene (TFB). The TPB-TFB COF thin films demonstrate high photoconductivity with a long charge scattering time exceeding 70 fs at room temperature which resembles crystalline inorganic materials. This corresponds to a record charge carrier mobility of 165 ± 10 cm 2 V -1 s -1 , vastly outperforming that of the state-of-the-art conductive COFs. These results reveal TPB-TFB COF thin films as promising candidates for organic electronics and catalysis and provide insights into the rational design of highly crystalline porous materials for efficient and long-range charge transport.