High‐Efficiency Semitransparent Near‐Infrared Organic Photodetectors Enabled by a Molecular Crystal Network

Abstract Semitransparent organic photodetectors (ST‐OPDs) show immense promise for integration into optoelectronic devices, offering adjustable absorption and see‐through functionalities. However, achieving high‐performance ST‐OPDs remains challenging, necessitating a delicate balance of low dark current density, high external quantum efficiency, and optimal visible light transmission. Here, a strategy is presented using anode interfacial materials (AIMs) as the donor and narrow bandgap non‐fullerene acceptors (NFAs) to formulate the donor: acceptor light‐sensitive layer. Critical to the approach is the incorporation of 1,8‐diiodooctane during film processing, enabling the formation of morphology with an NFA molecular crystal network embedded within the donor polymer matrix. This optimized morphology substantially boosted device external quantum efficiency and reduced dark current under reverse bias, yielding a remarkable special detectivity of over 10 13 Jones at 840 nm under a bias of −0.1 V. ST‐OPDs are achieved with detectivity surpassing 10 12 Jones and notable average visible transmittance of over 50%. These findings highlight the potential of AIM:NFA combinations for high‐efficiency ST‐OPDs by finely controlling morphology through multiple length scales, opening doors for various applications in transparent electronics and beyond.