An A–D–A′–D–A-Type Narrow Bandgap Electron Acceptor Based on Selenophene-Flanked Diketopyrrolopyrrole for Sensitive Near-Infrared Photodetection

Abstract

Near-infrared organic photodetectors possess great application potential in night vision, optical communication, and image sensing, but their development is limited by the lack of narrow bandgap organic semiconductors. A−D−A′−D−A-type molecules, featuring multiple intramolecular charge transfer effects, offer a robust framework for achieving near-infrared light absorption. Herein, we report a novel A−D−A′−D−A-type narrow bandgap electron acceptor named DPPSe-4Cl, which incorporates a selenopheneflanked diketopyrrolopyrrole (Se-DPP) unit as its central A′ component. This molecule demonstrates exceptional near-infrared absorption properties with an absorption onset reaching 1120 nm and a low optical bandgap of 1.11 eV, owing to the strong electronwithdrawing ability and quinoidal resonance effect induced by the Se-DPP unit. By implementing a doping compensation strategy assisted by Y6 to reduce the trap density in the photoactive layer, the optimized organic photodetector based on DPPSe-4Cl exhibited efficient spectral response and remarkable sensitivity in the range of 300−1100 nm.Particularly, a specific detectivity surpassing 10 12 Jones in the wavelength range of 410−1030 nm is achieved. This work offers a promising approach for developing highly sensitive visible to near-infrared broadband photodetection technology using organic semiconductors.

The revival of 4H-cyclopenta[2,1-b:3,4-b′]dithiophene (CPDT) driven by low-cost and high-performance nonfused-ring electron acceptors

“…Finally, CPDT-based NFREAs, with tunable optical and electrochemical properties, demonstrate great potential for diverse applications such as high-performance indoor OSCs and organic photodetectors, thereby meriting further investigation and exploration. [203][204][205][206] Overall, we can expect a fast development of CPDT-based photovoltaic materials, which have the potential to further enhance the photovoltaic performance and contribute to the commercial application of OSCs.…”

Fluorinated Conjugated Polymers Enabled Enhanced Detectivity in Organic Near-Infrared Photodetectors

“…Organic photodetectors (OPDs) have attracted significant interest from both academia and industry due to their excellent optoelectronic performance, solution processability, tunable response range, and large-area fabrication. − With the development of optoelectronics technology, OPDs have broad application in fields such as biomedical imaging, optical communications, and environmental monitoring. − One of the most significant advantages of OPDs is their synthetic flexibility, which allows for the preparation of different p/n-type organic semiconductors through design and combination of building blocks. This feature can be used to customize various performance parameters of OPDs, such as dark current, detectivity ( D* ), and spectral selectivity. − …”