Near-infrared organic photoelectric materials for light-harvesting systems: Organic photovoltaics and organic photodiodes

The inherent advantages of organic optoelectronic materials endow light-harvesting systems, including organic photovoltaics (OPVs) and organic photodiodes (OPDs), with multiple advantages, such as low-cost manufacturing, light weight, flexibility, and applicability to large-area fabrication, make them promising competitors with their inorganic counterparts. Among them, near-infrared (NIR) organic optoelectronic materials occupy a special position and have become the subject of extensive research in both academia and industry. The introduction of NIR materials into OPVs extends the absorption spectrum range, thereby enhancing the photon-harvesting ability of the devices, due to which they have been widely used for the construction of semitransparent solar cells with single-junction or tandem architectures. NIR photodiodes have tremendous potential in industrial, military, and scientific applications, such as remote control of smart electronic devices, chemical/biological sensing, environmental monitoring, optical communication, and so forth. These practical and potential applications have stimulated the development of NIR photoelectric materials, which in turn has given impetus to innovation in light-harvesting systems. In this review, we summarize the common molecular design strategies of NIR photoelectric materials and enumerate their applications in OPVs and OPDs. image