Low-Band gap Conjugated Polymers with Strong Absorption in the Second Near-Infrared Region Based on Diketopyrrolopyrrole-Containing Quinoidal Units

The development of low-band gap conjugated polymers with strong absorption in the second near-infrared (NIR-II) region is a big challenge because of the scarcity of an effective molecular design strategy. In the current paper, a series of conjugated polymers based on diketopyrrolopyrrole-containing quinoidal compounds have been synthesized and characterized. These polymers exhibited strong absorption in the NIR-II region with the absorption maxima above 1000 nm and optical band gaps as low as 0.84 eV. Owing to their strong near-infrared absorption, the polymers exhibited high photothermal conversion efficiencies of up to 53.1% upon 1064 nm laser irradiation (1 W cm(-2)). Top-gate and bottom-contact organic thin-film transistors (OTFTs) were fabricated to investigate their semiconducting properties. All the polymers showed ambipolar charge transport characteristics with reliable mobilities on the order of 10(-1) cm(2) V-1 s(-1). Low optical band gaps, high photothermal conversion efficiencies, and good charge transport properties endow these polymers with great potential in organic electronics and bio-related applications.

Automated summary

The paper describes the synthesis and characterization of a series of conjugated polymers with strong absorption in the NIR-II region. These polymers exhibit low optical band gaps, high photothermal conversion efficiencies, and reliable charge transport properties, making them promising for applications in organic electronics and bio-related fields.