Conductive coordination polymers(CCPs)have shown great potential for electronic purposes.However,their applications in photodetection have been limited by poor sensitivity,low on/off current ratio,and slow response owing to the low charge generation and/or separation efficiency.In this work,metal-to-ligand chargetransfer(MLCT)in PhSeAg was used to fabricate a single-component MLCT photodetecting material for the first time to solve the above challenges.The material obtained possesses ultrahigh sensitivity to weak-light intensity(0.03 mW cm^(−2)),the highest on/off ratio,and the fastest response speed than other wellknown CCPs materials tested.Our work might provide a simple but common strategy for designing high-performance CCPs composites for optoelectrical applications.