Combinatorial Screening and QSAR Modeling in the SrO–B[sub 2]O[sub 3]–P[sub 2]O[sub 5] Ternary System to Search for Thermally Stable Blue Phosphors for PDPs

Abstract

The need to identify a thermally stable blue phosphor for plasma display panels (PDPs) is vital, because the currently used BaMgAl10normalO17:normalEu2+ (BAM) phosphors have serious thermal degradation problems. In this respect, we report on the screening of a Eu2+ -doped SrO–normalB2normalO3–normalP2normalO5 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–normalB2normalO3–normalP2normalO5 ternary library, and the samples in this composition range were crystallized into a single major phase of Sr6BnormalP5normalO20:Eu2+ in an I4false¯c2 symmetry with cell parameters a=9.784 and c=19.01 . The luminance of Sr6BnormalP5normalO20: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.

Intense Red and Yellow Emissions from Sr[sub 2]SiO[sub 4]:Eu[sup 3+](Eu[sup 2+]) Electrospun Nanofibers

“…They exhibit a single-exponential decay profile, and the decay lifetime of Eu 2+ ions in Sr 2 SiO 4 :0.03 Eu 2+ nanofibers is about 10.9 s, which is analogous to the characteristic lifetime for the f-d emission of Eu 2+ ions. 30,31 From the results reported above, it can be deduced that these Sr 2 SiO 4 :xEu 2+ electrospun nanofibers with an intense yellow emission are potentially used as one-dimensional white LEDs in photoelectric micro-/nanodevices. Furthermore, due to the part orientation of crystal grains in Sr 2 SiO 4 :xEu nanofibers, the single Sr 2 SiO 4 :xEu nanofiber with intense red and yellow emissions potentially can be used as a linearly polarized light resource in photoelectric micro-/ nanodevices.…”

Composition-induced valence variation of europium and the photoluminescence properties for Eu2+ doped borophosphate luminous glass in air

“…First, the electrons are available from the matrix or synthetic atmosphere to enable the reduction from Eu 3+ to Eu 2+ ; second, the matrix should have a capability to offer a stable lattice environment for the Eu 2+ . Therefore it is considered that the special structure [ ] tetrahedral unit in silicate glasses, and form three-dimensional network which plays an important role in the stability of rare earth ions [13,14] . When the ratio of B/P exceeds 1.4, however, the glass structure tends to deviate from the suitable structure, resulting in a decrease in the intensity of blue emission.…”

“…As to where the Eu ions exist in the multiphase and multi-component system of borophosphate glass ceramics, we propose that the Eu ions in the glass-ceramics can exist in the sites of the glassy phase, the sites inside the nanocrystals and the sites localized at the interface between the crystal particles and the glassy phase [13][14][15][16][17] . With the amount of B 2 O 3 increases, the amount of Sr(PO 3 ) 2 crystal increases, which indicates the increase of Eu 2+ to substitute the more sites of Sr 2+ in the crystalline phase to intensify the blue emission.…”

Development of a high throughput environment for the optimization of process parameters for the solvothermal synthesis of isomerization catalysts

“…Although design of experiment (DOE) methodologies are common tools in the area of process optimization and commercial materials development12–18, only a few applications of these methods can be found in the area of combinatorial science19–21. In this area, the use of complex mathematical and statistical tools such as artificial neural networks4, 6, 22–28 is common; however, they require large datasets of low noise29, which is a challenging task in high throughput experimentation.…”