The need to identify a thermally stable blue phosphor for plasma display panels (PDPs) is vital, because the currently used BaMgAl10O17:Eu2+ (BAM) phosphors have serious thermal degradation problems. In this respect, we report on the screening of a Eu2+-doped SrO-B2O3-P2O5 system by a combinatorial chemistry technique so that combinatorial libraries could be developed in terms of luminance and color chromaticity. As a quantitative structure activity relationship (QSAR) model, a continuous luminance map was obtained as a function of composition using an artificial neural network trained using the results from the combinatorial screening. Promising photoluminescence was found in a lineshape composition range in the SrO-B2O3-P2O5 ternary library, and the samples in this composition range were crystallized into a single major phase of Sr6BP5O20:Eu2+ in an I $(4) over bar $ c2 symmetry with cell parameters a=9.784 and c=19.01. The luminance of Sr6BP5O20:Eu2+ was 2.8 times as high as BAM under vacuum ultraviolet (VUV) excitation and underwent negligible thermal degradation, even though the CIE color chromaticity was somewhat poor. (c) 2005 The Electrochemical Society. All rights reserved.