PBDT

PBDt, often written as PBDT, refers to polybenzodithiophene, a family of conjugated polymers based on the benzodithiophene (BDT) unit. These polymers are built from benzodithiophene cores linked to various co-monomers to form alternating or copolymer backbones. The BDT unit provides planarity and strong pi-conjugation, which support charge transport in solid films.

In synthesis, PBDT polymers are typically prepared by palladium-catalyzed cross-coupling polymerization methods such as Suzuki or Stille couplings, using monomers that contain benzodithiophene cores coupled with thiophene or other heterocycles. Side chains, often alkyl groups, are introduced to improve solubility and film-forming properties, enabling solution processing.

Properties of PBDT polymers include strong absorption in the visible to near-infrared region, tunable HOMO and LUMO energy levels depending on the co-monomers and substituents, and potentially high hole mobility in thin films. The solid-state packing and crystallinity can be controlled via side-chain engineering, which in turn influences optoelectronic performance.

Applications for PBDT-based materials span organic electronics, particularly as donor components in organic photovoltaic cells, as active layers in thin-film transistors, and in photodetectors. They are valued for tunable energy levels, good film-forming properties, and relatively good stability among conjugated polymers.

Derivatives of PBDT involve modifying the backbone with various co-monomers or functional groups to tune optical gaps, energy levels, and solubility. Common modifications include different alkyl or alkoxy side chains and incorporation of electron-accepting units to create donor–acceptor copolymers.

See also: benzodithiophene, conjugated polymers, organic photovoltaics.