We introduce the concept, as well as the methodology, of using a mineral-inspired approach in combination with solution parallel synthesis for the exploration of new phosphors. The key to successful discovery of new phosphors is the construction of a promising composition library. In this chapter, the construction of an artificial composition library inspired by minerals is proposed. By employing this approach, we have discovered various new phosphors including NaAlSiO4:Eu2+, BaZrSi3O9:Eu2+, Na3ScSi3O9:Eu2+, SrCaSiO4:Eu2+, and Ca2SiO4: Eu2+ that emit green-yellow (553 nm), cyan blue-green (480 nm), green (520 nm), orange-red (615 nm), and deep-red (650 nm) light, respectively, when excited at 365–460 nm. Among these phosphors, the most prominent result was the observation of unusual deep-red emission from Ca2SiO4:Eu2+, which originated from the phase transition from the normal β-phase to an α′l-phase when a sizable number of Ca2+ sites were substituted by Eu2+ (up to 40 mol%). The reason for the emergence of the deep-red emission of α′l-Ca2SiO4:Eu2+ is discussed in terms of “crystal site engineering.” In addition to these silicate-based phosphors, exploration of new oxide up-conversion phosphors was carried out using solution parallel synthesis. Among various niobates and tantalates of rare earth elements, Y0.5Yb0.4Er0.1Ta7O19 was discovered as a new oxide up-conversion phosphor with a good internal quantum efficiency (2.05 %) compared with those of previously known up-conversion phosphors, which are typically below 1 %.
|Title of host publication||Phosphors, Up Conversion Nano Particles, Quantum Dots and Their Applications|
|Number of pages||40|
|Publication status||Published - 2016 Jan 1|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Materials Science(all)