ExperimentalThe overall process of the combi-chem system adopted in the present investigation is described in more detail in our previous reports [11±17]. The Eu, Si, and Ca solutions were prepared by dissolving Eu 2 O 3 (0.1 mol), Si(C 2 H 5 O) 4 -(TEOS) (0.5 mol), and CaCO 3 (0.5 mol) in nitric acid. The Mg, Sr, Ba, and B solutions were prepared by dissolving Mg(NO 3 ) 2´6 H 2 O (0.5 mol), Sr(NO 3 ) 2 (0.5 mol), Ba(NO 3 ) 2 (0.25 mol), and H 3 BO 3 (0.5 mol) in deionized water. The appropriate amount of each solution was then injected into a 6 mL test tube array according to the composition table with the assistance of a computer programmed injection system (108 different compositions per generation were used). The solutions in the tubes were dried at 80 C for 24 h. At this stage gelation took place for those compositions that contained more than 0.3 mol of Si, but the others were simply dried. These samples were further dried at 600 C for 2 h. The dried samples were pulverized and collected in a specially designed ceramic container (given the name ªcombi-chemº container) and successively fired at 900 C for 2 h in an ambient atmosphere. The firing temperature was selected out of several other temperatures such as 900, 1000, 1100, and 1200 C in view of the average and maximum luminance value of the first generation. Some of the samples chosen among the library were removed from the combichem containers and examined by XRD and scanning electron microscopy (SEM) analyses. The emission spectra and the decay curves were monitored at 400 nm, which simulates an InGaN LED light source, with the samples being left in the combi-chem containers using a plate reader accessory attached to a Perkin Elmer LS50B spectrometer with a xenon flash lamp. The luminance was calculated by integrating the product of the emission spectrum and the standard visual spectral efficiency curve based on CIE (Commission Internationale de l'Eclairage) regulation [25].