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Two‐dimensional conjugated metal–organic frameworks (2D c‐MOFs) are emerging as a unique class of electronic materials. However, 2D c‐MOFs with band gaps in the Vis‐NIR and high charge carrier mobility are rare. Most of the reported conducting 2D c‐MOFs are metallic (i.e. gapless), which largely limits their use in logic devices. Herein, we design a phenanthrotriphenylene‐based, D2h‐symmetric π‐extended ligand (OHPTP), and synthesize the first rhombic 2D c‐MOF single crystals (Cu2(OHPTP)). The continuous rotation electron diffraction (cRED) analysis unveils the orthorhombic crystal structure at the atomic level with a unique slipped AA stacking. The Cu2(OHPTP) is a p‐type semiconductor with an indirect band gap of ≈0.50 eV and exhibits high electrical conductivity of 0.10 S cm−1 and high charge carrier mobility of ≈10.0 cm2 V−1 s−1. Theoretical calculations underline the predominant role of the out‐of‐plane charge transport in this semiquinone‐based 2D c‐MOF. [ABSTRACT FROM AUTHOR]

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We explore the charge transport properties of phytic acid (PA) doped polyaniline thin films prepared by the surfactant monolayer‐assisted interfacial synthesis (SMAIS). Structural and elemental analysis confirms the inclusion of PA in the thin films and reveals a progressive loss of crystallinity with the increase of PA doping content. Charge transport properties are interrogated by time‐resolved terahertz (THz) spectroscopy. Notably, independently of doping content and hence crystallinity, the frequency‐resolved complex conductivity spectra in the THz region can be properly described by the Drude model, demonstrating band‐like charge transport in the samples and state‐of‐the‐art charge carrier mobilities of ≈1 cm2V−1s−1. A temperature‐dependent analysis for the conductivity further supports band‐like charge transport and suggest that charge carrier mobility is primarily limited by impurity scattering. This work highlights the potential of PA doped polyaniline for organic electronics. [ABSTRACT FROM AUTHOR]

Single‐layer and multi‐layer 2D polyimine films have been achieved through interfacial synthesis methods. However, it remains a great challenge to achieve the maximum degree of crystallinity in the 2D polyimines, which largely limits the long‐range transport properties. Here we employ a surfactant‐monolayer‐assisted interfacial synthesis (SMAIS) method for the successful preparation of porphyrin and triazine containing polyimine‐based 2D polymer (PI‐2DP) films with square and hexagonal lattices, respectively. The synthetic PI‐2DP films are featured with polycrystalline multilayers with tunable thickness from 6 to 200 nm and large crystalline domains (100–150 nm in size). Intrigued by high crystallinity and the presence of electroactive porphyrin moieties, the optoelectronic properties of PI‐2DP are investigated by time‐resolved terahertz spectroscopy. Typically, the porphyrin‐based PI‐2DP 1 film exhibits a p‐type semiconductor behavior with a band gap of 1.38 eV and hole mobility as high as 0.01 cm2 V−1 s−1, superior to the previously reported polyimine based materials. [ABSTRACT FROM AUTHOR]

On-chip micro-supercapacitors (MSCs) are important Si-compatible power-source backups for miniaturized electronics. Despite their tremendous advantages, current on-chip MSCs require harsh processing conditions and typically perform like resistors when filtering ripples from alternating current (AC). Herein, we demonstrated a facile layer-by-layer method towards on-chip MSCs based on an azulene-bridged coordination polymer framework (PiCBA). Owing to the good carrier mobility (5×10−3 cm2 V−1 s−1) of PiCBA, the permanent dipole moment of azulene skeleton, and ultralow band gap of PiCBA, the fabricated MSCs delivered high specific capacitances of up to 34.1 F cm−3 at 50 mV s−1 and a high volumetric power density of 1323 W cm−3. Most importantly, such MCSs exhibited AC line-filtering performance (−73° at 120 Hz) with a short resistance-capacitance constant of circa 0.83 ms. [ABSTRACT FROM AUTHOR]

On-chip micro-supercapacitors (MSCs) are important Si-compatible power-source backups for miniaturized electronics. Despite their tremendous advantages, current on-chip MSCs require harsh processing conditions and typically perform like resistors when filtering ripples from alternating current (AC). Herein, we demonstrated a facile layer-by-layer method towards on-chip MSCs based on an azulene-bridged coordination polymer framework (PiCBA). Owing to the good carrier mobility (5×10−3 cm2 V−1 s−1) of PiCBA, the permanent dipole moment of azulene skeleton, and ultralow band gap of PiCBA, the fabricated MSCs delivered high specific capacitances of up to 34.1 F cm−3 at 50 mV s−1 and a high volumetric power density of 1323 W cm−3. Most importantly, such MCSs exhibited AC line-filtering performance (−73° at 120 Hz) with a short resistance-capacitance constant of circa 0.83 ms. [ABSTRACT FROM AUTHOR]

Among the rising 2D soft materials, conjugated polymer nanosheets are one of the most promising and new classes of polymeric materials, which are rarely developed because of the challenge in controlling the dimensionality and lack of synthetic strategies. In this study, one kind of sulfur-enriched conjugated polymer nanosheet (2DP-S) with a high aspect ratio of up to ≈400 is successfully synthesized. On the basis of structural characterization, as-prepared 2DP-S possesses the chemical identity of cruciform-fused polymeric backbone consisting of quinoidal polythiophene and poly( p-phenylenevinylene) along horizontal and vertical directions, respectively, by sharing two alternating single-double carbon-carbon bonds in each repeat unit. The unique structural conformation of 2DP-S renders carrier mobilities of up to 0.1 ± 0.05 cm2 V−1 s−1, a figure inferred from Terahertz time domain spectroscopy. Moreover, upon thermal treatment, 2DP-S is readily converted into N/S dual-doped porous carbon nanosheets (2DPCs) under ammonia atmosphere, whose N/S ratio can be rationally controlled by adjusting the activation time. The catalytic performance of the oxygen reduction reaction of as-prepared 2DPCs is well tunable by the rationally controlled N/S contents. These results offer a new pathway for exploring heteroatom-doped porous carbons applicable for energy conversion and storage. [ABSTRACT FROM AUTHOR]

2D soft nanomaterials are an emerging research field due to their versatile chemical structures, easily tunable properties, and broad application potential. In this study, a benzene‐bridged polypyrrole film with a large area, up to a few square centimeters, is synthesized through an interfacial polymerization approach. As‐prepared semiconductive films exhibit a bandgap of ≈2 eV and a carrier mobility of ≈1.5 cm2 V−1 s−1, inferred from time‐resolved terahertz spectroscopy. The samples are employed to fabricate in‐plane micro‐supercapacitors (MSCs) by laser scribing and exhibit an ultrahigh areal capacitance of 0.95 mF cm−2, using 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([EMIM][BF4]) as an electrolyte. Importantly, the maximum energy and power densities of the developed MSCs reach values up to 50.7 mWh cm−3 and 9.6 kW cm−3, respectively; the performance surpassing most of the 2D material‐based MSCs is reported to date. [ABSTRACT FROM AUTHOR]

2D conjugated metal–organic frameworks (2D c‐MOFs) are emerging as unique electroactive materials for electronics and spintronics. The structural design and discovery of Kagome‐type 2D c‐MOFs exhibiting a metallic state are of paramount significance, yet remain rarely explored. Here, the solution synthesis of benzenehexol‐based 2D c‐MOFs based is presented on the tetrahydroxy‐1,4‐quinone (THQ) ligand. This study shows that controlling the pH of the reaction system to ≈7.5 yields an energetically favorable nonporous Cu3(C6O6) with a Kagome lattice, while at a pH of ≈10, the known porous Cu3(C6O6)2 with a honeycomb lattice is obtained. The crystal structures of both Cu3(C6O6)2 and Cu3(C6O6) are resolved with near‐atomic precision (resolution, 1.8 Å) using an imaging technique. Unlike the p‐type semiconducting behavior of Cu3(C6O6)2, theoretical studies identify Cu3(C6O6) as a metal due to its unique structural topology. The metallic state of Cu3(C6O6) is experimentally validated by terahertz time‐domain spectroscopy (THz‐TDS), which shows an increase in conductivity upon cooling. Scattering‐type scanning near‐field optical microscopy (s‐SNOM) measurements further support these findings by revealing an increase in normalized reflectivity with decreasing temperature. This work provides a new avenue for tailoring the structural topology of 2D c‐MOFs to attain the Kagome lattice and metallic state. [ABSTRACT FROM AUTHOR]