Publication date: 11th July 2022
Quasi-two-dimensional conjugated polymers (q2DCPs) consist of 2D layered structures formed by the assembly of linear conjugated polymer chains via non-covalent bonds. They attracted increasing attention in recent years due to their outstanding physical properties, such as 2D coherent charge transport, high electrical conductivity, and significant enhancement of thermoelectric power factors. Polypyrrole (PPy) is one of the most studied linear conjugated polymers due to its unique optical and electrical properties associated with broad applications. However, it has remained largely unexplored to develop structurally defined PPy-based q2DCPs, referred to as quasi-two-dimensional polypyrrole (q2DPPy) due to challenges in synthesis, such as the helical conformation of PPy chain, side reaction and insufficient doping. In this work, we demonstrate the synthesis of novel q2DPPy films through oxidation polymerization of pyrrole on a concentrated sulphuric acid surface. Aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM), grazing-incidence wide-angle X-ray scattering (GIWAXS) and density functional based tight-binding (DFTB) calculation indicate that the q2DPPy film is formed by layered assembly of protonated quinoidal chains with fully stretched conformation. The pyrrole unit of q2DPPy presents a fully cationic form compensated by HSO4- with a theoretically maximum doping level of n(HSO4-)/n(Py+) ≈ 1:1. This unique chain conformation and high doping level lead to a narrow bandgap and significant light absorbance of the q2DPPy film in the near-infrared (NIR) region. Remarkably, the resulting q2DPPy film displays record-high mobility of 31.68 cm2V-1s-1 by time-resolved terahertz spectroscopy (TRTS). We believe that this work is of general interest to a broad range of readers in 2D materials, conjugated polymer materials, supramolecular chemistry and physical science. We hope that you will share our excitement about the scientific breakthrough achieved in the present work.
We acknowledge financial support from EU Graphene Flagship (Core3, No. 881603), ERC Grants on T2DCP and FC2DMOF (No. 852909) and DFG projects (SFB-1415, No. 417590517) as well as the German Science Council, Centre of Advancing Electronics Dresden, EXC1056 (Center for Advancing Electronics Dresden) and OR 349/1. We acknowledge Dresden Center for Nanoanalysis (DCN) for scanning electron microscopy and Dr. Petr Formanek (Leibniz Institute for Polymer Research, IPF, Dresden) for the use of facilities. We acknowledge Elettra Sincrotrone Trieste for providing access to its synchrotron radiation facilities and we thank Luisa Barba for assistance in using beamline XRD1. The research leading to this result has been supported by the project CALIPSOplus under Grant Agreement 730872 from the EU Framework Program for Research and Innovation HORIZON 2020. Open access funding enabled and organized by Projekt DEAL.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.