Non‐symmetric Half‐Fused B←N Coordinated Diketopyrrolopyrrole Building Block for n‐type Semiconducting Polymers

Abstract

The development of conjugated polymers with high semiconducting performance and high reliability is of great significance for flexible electronics. Herein, we developed a new type of electron-accepting building block; i.e., non-symmetric half-fused B ! N coordinated diketopyrrolopyrrole (DPP) (HBNDPP), for amorphous conjugated polymers toward flexible electronics. The rigid B ! N fusion part of HBNDPP endows the resulting polymers with decent electron transport, while its non-symmetric structure causes the polymer to exhibit multiple conformation isomers with flat torsional potential energies. Thus, it gets packed in an amorphous manner in solid state, ensuring good resistance to bending strain. Combined with hardness and softness, the flexible organic field-effect transistor devices exhibit n-type charge properties with decent mobility, good bending resistance, and good ambient stability. The preliminary study makes this building block a potential candidate for future design of conjugated materials for flexible electronic devices.

Boron- and Nitrogen-Embedded Polycyclic Arenes as an Emerging Class of Organic Semiconductors

“…It is difficult to modulate HOMO/LUMO energies to a large extent (>0.5 eV) in conjugated polymers, and consequently, only limited n-type polymers show low-lying LUMO energies. The incorporation of the coordinate B ← N bond is a powerful strategy to lower the LUMO levels of conjugated polymers. − Liu and co-workers first demonstrated this concept by using polymer 19 as a model structure (Figure a) . After replacing a C–C bond in 18 with a B ← N unit, the LUMO energy ( E LUMO ) was dramatically down-shifted from −3.11 to −3.76 eV, which was comparable to the commonly used electron acceptor phenyl-C 61 -butyric acid methyl ester ( E LUMO = −3.88 eV).…”

Control over the aggregated structure of donor–acceptor conjugated polymer films for high‐mobility organic field‐effect transistors

“…Chemical methods to control the film microstructure of near-amorphous conjugated polymers include varying the side chains, the backbone units, and the molecular weight. [20,[173][174][175][176][177] Here, we mainly focus on physical methods to optimize the aggregated structure of near-amorphous D-A conjugated polymer films, such as improving the size and connectivity of aggregates, promoting the alignment of polymer chains and decreasing the density of traps. Table 2 summarizes the chemical structure, improvement of aggregated structure, the average mobility, and OFET type of near-amorphous D-A conjugated polymers via different strategies, which we will discuss in turn.…”

A skeletal randomization strategy for high-performance quinoidal-aromatic polymers

“…The pursuit of high-performing conjugated polymers (CPs) has been central to the advancement of organic solar cells (OSCs), 1–3 organic field-effect transistors (OFETs) 4–6 and other electronic devices. 7–9 Recently, OFETs have shown promising potential for their use as driving circuits for large-area flexible displays and other types of flexible electronics, the performance of which is largely determined by the CPs utilized in the active layer.…”

“…The pursuit of high-performing conjugated polymers (CPs) has been central to the advancement of organic solar cells (OSCs), [1][2][3] organic field-effect transistors (OFETs) [4][5][6] and other electronic devices. [7][8][9] Recently, OFETs have shown promising potential for their use as driving circuits for large-area flexible This paper introduces an innovative concept in the design of high mobility conjugated polymer research, challenging the conventionally perceived trade-off between solubility and crystallinity that has long constrained the practicality of conjugated polymers.…”