This book is the first standalone volume on organic narrowband photodetectors, providing a comprehensive and up-to-date overview of the field and its applications. The book introduces the light-sensing capabilities of organic semiconductors and examines the principles of organic narrowband photodetection including newly developed unified categorisation of the associated narrowband strategies. The book discusses the large range of compounds, diverse device configurations, and real-world applications that have been explored with organic narrowband photodetectors. The most extensive tabulated collection of organic narrowband photodetector performance data published to date is also provided. This book is well suited to researchers and practitioners in optoelectronics, organic semiconductors, and related fields, as well as technology enthusiasts and students in physics, electronics engineering, chemistry, and materials science.