A Pentacyclic Nitrogen-Bridged Thienyl-Phenylene-Thienyl Arene for Donor-Acceptor Copolymers: Synthesis, Characterization, and Applications in Field-Effect Transistors and Polymer Solar Cells

High-performance five-ring-fused organic semiconductors for field-effect transistors

Organic molecular semiconductors have been paid great attention due to their advantages of low-temperature processability, low fabrication cost, good flexibility, and excellent electronic properties. As a typical example of five-ring-fused organic semiconductors, a single crystal of pentacene shows a high mobility of up to 40 cm² V^-1 s^-1, indicating its potential application in organic electronics. However, the photo- and optical instabilities of pentacene make it unsuitable for commercial applications. But, molecular engineering, for both the five-ring-fused building block and side chains, has been performed to improve the stability of materials as well as maintain high mobility. Here, several groups (thiophenes, pyrroles, furans, etc.) are introduced to design and replace one or more benzene rings of pentacene and construct novel five-ring-fused organic semiconductors. In this review article, ∼500 five-ring-fused organic prototype molecules and their derivatives are summarized to provide a general understanding of this catalogue material for application in organic field-effect transistors. The results indicate that many five-ring-fused organic semiconductors can achieve high mobilities of more than 1 cm² V^-1 s^-1, and a hole mobility of up to 18.9 cm² V^-1 s^-1 can be obtained, while an electron mobility of 27.8 cm² V^-1 s^-1 can be achieved in five-ring-fused organic semiconductors. The HOMO-LUMO levels, the synthesis process, the molecular packing, and the side-chain engineering of five-ring-fused organic semiconductors are analyzed. The current problems, conclusions, and perspectives are also provided.

Amide-bridged terphenyl and dithienylbenzene units for semiconducting polymers

Semiconducting polymers with new “electron-neutral” amide-bridged building units were designed, synthesized, and studied as materials for organic devices.

Donor–acceptor conjugated polymers based on multifused ladder-type arenes for organic solar cells

In this review, we summarize the recent development of the multifused ladder-type conjugated building blocks for making donor–acceptor conjugated copolymers.

S,N-Heteropentacene based small molecules with A–D–A structure for solution processed organic bulk heterojunction solar cells

SN(BTTh₂)₂ and SN(BTAOTh₂)₂, containing an electron rich planar S,N-heteropentacene flanked with alkoxy substituted and unsubstituted benzothiadiazole and end capped with hexyl-substituted bi-thiophene units, were designed and synthesized.