Genetic Algorithm-Assisted Combinatorial Search for New Blue Phosphors in a(Ca,Sr,Ba,Mg,Eu)_xB_yP_zO_(delta)System

摘要

Genetic algorithm-assistedcombinatorial chemistry(GACC)was implemented to search for new blue phosphors in seven cation systems,including CaO,MgO,BaO,SrO,B2O3,P2O5,and Eu2O3.The GACC process was followed by a series of fine-tuning processes based on conventional high-throughput screening employing quaternary and ternary libraries,to pinpoint promising compositions.GACC was found to be useful as a preliminary step for final screening.This series of processes involving computations and actual syntheses led us to(Sr_(1-x-y)Ca_xBa_y)_2P2O7:Eu~(2+)(0.32 < x < 0.72,y < 0.04)phosphors.It was found that the boron addition played a significant role in enhancing the luminance but it was completely evaporated during the synthesis,and an excessive amount of alkali earth elements was essential for better luminescence.The luminance of(Sr_(1-x-y)Ca_xBa_y)_2P2O7:Eu~(2+)(0.32 < x < 0.72,y < 0.04)phosphors reached 70 of a commercially available BAM phosphor at 254 nm excitation.The color chromaticity was in the deep blue region,x = 0.15,y = 0.05.The structure of these phosphors was found to be Sr2P2O7(Pnma,62),but the luminescent property was far better than the Sr2P2O7:Eu~(2+)phosphor.