Rare-Earth-Free Barium Borostannate with Deep-Blue Light Emission

Playing a crucial role in light-emitting diode (LED) illumination sources, the blue light-emitting materials are commonly obtained by doping rare-earth metal ions. Considering the high price, non-renewable supply, and unstable oxidation state of rare-earth metal ions, developing economically and environmentally amicable as well as steady blue light-emitting materials is of great significance. Herein, we have proposed a new structural design strategy of introducing Sn⁴⁺ cations into borates and have successfully constructed a novel barium borostannate, Ba₇Sn­(BO₃)₆. Notably, this is the first SnO₆-activated rare-earth-free deep-blue light-emitting borostannate with extremely high emission energy. By combining Ba₇Sn­(BO₃)₆ with other commercial phosphors, a series of white LED devices were successfully fabricated. This promising material will provide a new approach in the development of LED applications.