Engineering graphitic carbon nitride for next-generation photodetectors: a mini review

Semiconductor photodetectors, as photoelectric devices using optical-electrical signal conversion for detection, are widely used in various fields such as optical communication, medical imaging, environmental monitoring, military tracking, remote sensing, etc. Compared to the conventional photodetector materials including silicon, III-V semiconductors and metal sulfides, graphitic carbon nitride (g-C₃N₄) as a metal-free polymeric semiconductor, has many advantages such as low-price, easy preparation, efficient visible light response, and relatively good thermal stability. In the meantime, the polymer characteristics also endow the g-C₃N₄ with good mechanical properties. Apart from being used for photo(electro)catalysts during the past decades, the potential use of g-C₃N₄ in photodetectors has attracted great research interests very recently. In this review, we first briefly introduce the structure and properties of g-C₃N₄ and the key performance parameters of photodetectors. Then, combining the very recent progress, the review focuses on the active materials, fabrication methods and performance enhancement strategies for g-C₃N₄ based photodetectors. The existing challenges are discussed and the future development of g-C₃N₄ based photodetectors is also forecasted.