Anthra[2,1-b:3,4-b']Dithiophene-7,12-Dione-Based Polymer Donors: Boosting Responsivity and Thermal Stability for Organic Photodetectors

Polymer photodetectors hold great promise for applications in the field of flexible electronics. However, there is currently a notable absence of suitable polymer donors that can simultaneously meet the demands for high performance and thermal stability. Herein, a new optoelectronic building block, anthra[2,1-b:3,4-b']dithiophene-7,12-dione (ADTD), is synthesized. Subsequently, ADTD is used to construct quinone-containing polymers. Combined with the benefits of quinone characteristics and extended conjugation structure, this approach enhances molecular planarity and promotes π-electron delocalization. It effectively boosts charge transport capabilities. As a result, the chlorine-mediated polymer (ADTD-Cl) demonstrates a superior specific detectivity of up to 6.89×10¹³ Jones and an outstanding responsivity of 0.561 A W⁻¹, which is currently the outstanding responsivity value reported in binary organic photodetectors. More intriguingly, the lower trap state density and energy disorder of ADTD-Cl-based device contribute to its exceptional thermal stability, which can maintain over 80% of its initial value even after continuous heating at 65 °C for 1000 h. These findings indicate that the polymer donors with new ADTD functional units can facilitate attaining two key objectives for organic photodetectors: high performance and thermal stability. The emergence of those materials will undoubtedly greatly promote the further practical development of organic photodetectors.