Near-infrared light-emitting diodes (NIR-LEDs), as a key advancing technology, cover nearly all aspects of our daily life due to their supported large applications, such as biomedical imaging, optical communication, security, and data storage. However, the development of NIR-LEDs is modest due to the fundamental limitation of emitters. This project (MaDLED) aims to master the highly p-doped tin-halide perovskites (THPs) for achieving high-efficiency NIR-LEDs.