Multichannel Luminescence Properties of Mixed-Valent Eu/Eu Coactivated SrAlBO Nanocrystalline Phosphors for Near-UV LEDs.

Up to now, orchestrating the coexistence of Eu and Eu activators in a single host lattice has been an extremely difficult task, especially for the appearance of the characteristic emission of Eu and Eu in order to generate white light. Nevertheless, here we demonstrate a new Eu/Eu coactivated SrAlBO nanocrystalline phosphor with abundant and excellent multichannel luminescence properties. A series of Eu/Eu coactivated SrAlBO nanocrystalline phosphors were prepared through a Pechini-type sol-gel method followed by a reduction process. With excitation of UV/NUV light, the prepared SrAlBO:Eu,Eu phosphors show not only the characteristic f-f transitions of Eu ion (D → F, J, J' = 0-3), but also the 5d → 4f transitions of Eu ion with comparable intensity from 400 to 700 nm in the whole visible spectral region. The luminescence color of the SrAlBO:Eu,Eu phosphor can be tuned from blue, blue-green, white, and orange to orange-red by changing the excitation wavelength, the overall doping concentration of europium ions (Eu, Eu), and the relative ratio of Eu to Eu ions to some extent. A single-phase white-light emission has been realized in SrAlBO:Eu,Eu phosphor. The obtained SrAlBO:Eu,Eu phosphor has potential application in the area of NUV white-light-emitting diodes.