Research Progress of Near-infrared Organic Photovoltaic Photodetectors

Photodetectors are the foundation of modem science and industrial systems. Organic semiconductors have developed rapidly in the past decade due to their appealing properties such as low-cost manufacturing, flexibility, light-weight, and large-area scalability. Near-infrared organic photovoltaic photodetectors have drawn extensive attention because of their wide applications in bioimaging, quality inspection, image sensing, optical communication and night surveillance. Owing to the highly tuneable optical and electrical properties of organic semiconductor materials, narrow-band, low noise, visible-blind near-infrared organic photodetectors have been achieved. The research on near-infrared organic photovoltaic photodetectors has aroused widespread interest at home and abroad. Chinese scholars have made great contributions to the development of this research field, and a series of important innovations have been made in the preparation of near-infrared organic materials and the design of near-infrared organic photodiode devices. This article aims to summarize and review the research progress of near-infrared organic photovoltaic photodetectors and their future development in the fields of imaging sensing, biomedicine and spectral analysis. In the first section, we briefly introduce the basic overview of the device structures, applications and important figures of merit of organic photodetectors. In the second section, we summarized the materials used in the active layer of the near-infrared photovoltaic organic photodetectors in the past decade, which are simply classified into organic near-infrared polymer materials and near-infrared small-molecule materials. In the third section, we reviewed the device optimization and design strategies of near-infrared organic photovoltaic photodetectors, including the adjustment of active layer film thickness, charged carrier blocking layers, the strategies of charge collecting narrowing and exciton dissociation narrowing. In the fourth section, the specific applications and their scientific principles of near-infrared organic photodetectors are introduced, including real-time biological monitoring, spectral analysis and near-infrared imaging applications. In the last section, we briefly summarized the achievements which have been made, the current challenges and the future prospects of near-infrared organic photovoltaic photodetectors.