New Green Phosphor Ba_3Si_6O_(12)N_2:Eu for White LED: Crystal Structure and Optical Properties

摘要

A new oxynitride, Ba_3Si_6O_(12)N_2, has been synthesized. The crystal structure has been successfully determined by close collaboration between experiment and first-principles calculation. This compound doped with Eu exhibits intense green photoluminescence with high color purity under near-ultraviolet to blue light excitation; in particular, it has much less thermal quenching than (Ba,Sr,Eu)_2SiO_4. Thus (Ba,Eu)_3Si_6O_(12)N_2 appears promising green phosphor for white LED backlight for display. The atomic/electronic structure is discussed in comparison with Ba_3Si_6O_9N_4, which could not become efficient phosphor by doping Eu due to strong thermal quenching at room temperature.