분무열분해법으로 YAG:Ce 제조시 용액 조건이 발광특성에 미치는 영향

Abstract

YAG:Ce yellow phosphor particles were synthesized by spray pyrolysis with changing the solution properties and their luminous properties, crystal structure, and morphological changes were studied by using PL measurement, XRD, and SEM analysis. It was clear that the solution properties significantly affected the crystal phase, crystallite size, the PL intensity, and the morphology of YAG:Ce particles. At low calcination temperature, the addition of urea only to the spray solution was helpful to form a pure YAG phase without any impurity phases, as the result, the highest luminescence intensity was achieved at the calcination temperature of <TEX>$900^{\circ}C$</TEX>. When the calcination temperatures were larger than <TEX>$1300^{\circ}C$</TEX>, however, the YAG particles prepared without any additive showed the highest luminescent intensity. Regardless of the solution conditions, the emission intensity of YAG:Ce particles prepared by spray pyrolysis showed a linear relation with the crystallite size. In terms of the morphology of YAG:Ce particles, the addition of both DCCA and <TEX>$NH_4OH$</TEX> to the spray solution was effective to prepare a spherical and dense structured YAG particles.