Diketopyrrolopyrrole-based two-dimensional poly(arylene vinylene)s with high charge carrier mobility

TL;DR

Researchers designed new 2D polymer materials with high charge mobility and low band gaps, promising for electronics and photocatalysis.

Contribution

They introduced diketopyrrolopyrrole-based 2D poly(arylene vinylene)s with ultralow effective masses and high mobility.

Findings

The materials have optical band gaps as narrow as 1.0 eV.

Room-temperature charge carrier mobility reached 310 cm² V⁻¹ s⁻¹.

Theoretical predictions aligned with experimental terahertz spectroscopy results.

Abstract

Layered two-dimensional conjugated polymers (2D CPs), or 2D conjugated covalent organic frameworks, are promising semiconductor materials for (opto)electronics and photocatalysis, but their performance is often limited by insufficient in-plane conjugation and poor charge transport. Guided by density functional theory calculations, we report two donor-acceptor-type 2D poly(arylene vinylene)s constructed from thienyl-benzodithiophene and diketopyrrolopyrrole units. These materials are predicted to exhibit strongly dispersive energy bands with ultralow in-plane effective masses (0.036 − 0.159 m0), enabling intrinsic charge mobilities approaching 2000 cm2 V−1 s−1. Solid-state Aldol-type 2D polycondensation yields crystalline materials with optical band gaps as narrow as 1.0 eV. Terahertz spectroscopy reveals long charge carrier scattering times of 76 fs and a high room-temperature mobility of 310 cm2 V−1 s−1, surpassing previously reported linear and 2D CP powder samples. This work highlights donor-acceptor engineering as an effective strategy to enhance charge transport in 2D CPs.

2D polymer materials are often limited in performance by insufficient in-plane conjugation and poor charge transport. Guided by theoretical calculations, the authors present diketopyrrolopyrrole-based crystalline 2D poly(arylene vinylene)s with narrow optical band gaps of 1 eV and high charge carrier mobility.

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