Luminescent properties and mechanism of Gd _1-x-yAlO ₃:Tb _x,RE _y gradational combinatorial library

The combinatorial material library approach is an excellent innovation for inorganic functional material research, and it can discover and screen new materials efficiently. In this paper, it is used to quickly find and improve Tb ³⁺ activated gadolinium aluminate perovskite phosphors (Gd _1-x-yAlO ₃:Tb _x,RE _y, RE ion vary among Ce ^3+,4+, Dy ³⁺, abbreviate as GAP:Tb,RE). Under UV light excitation, Gd _1-x-yAlO ₃:Tb _x,RE _y gradational combinatorial library indentifies the "lead" green luminescent compound as GAP:Tb0.1 from all the GAP:Tbx (x=0.050.15) candidates in a quick way. Then the relationship between sensitizers and activators can be also mapped out quickly, that Dy ³⁺ is a good sensitizer for Tb3+ activator while Ce ^{3+, 4+}is not a suitable one. The photoluminescent excitation (PLE) and photoluminescent emission (PL) spectral indicate the resonance energy transfer between the activator and sensitizer must have happened, which leads to Ce ^3+,4+ co-doping decrease Tb3+ green luminescence( ⁵D ₄→ ⁷F ₅, 544nm) while Dy ³⁺ co-doping increase green luminescence. The candidates in the library are prepared in powder form by nitric-citric method for more detailed characterization. All the screening results, obtained from the combinational library, are coherent with the powder phosphor experiments.