The 314th MANA & the 134th ICYS Joint Seminar

Dr. Benjamin Dierre & Dr. Brian Richard Pauw

Date February 15, Friday
Time 15:30-16:30
Place Auditorium, 1F, WPI - MANA Building, Namiki Site, NIMS

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SiAlON-based phosphors for low-energy consumption light emitters

Light emitting diodes (LEDs) and field emission displays (FEDs) are attracting significant attention due to their improved performance and their lower power consumption. The key for such devices is a high-luminescent phosphor. Actually, the most commonly used are oxides and sulfides. However, most oxide-based phosphors have low performance, while sulfide-based ones suffer from degradation under ambient atmosphere. To solve their problems, we must develop new phosphors with better luminescence properties, good thermal and chemical stabilities, and environmental-friendly.

SiAlON materials have ever demonstrated as great candidates for the low-energy consumption light emitters.1 A great flexibility in the emission properties can be achieved by controlling their composition and dopants. But to optimize their performance and reduce their costs, it is necessary to correlate more precisely the luminescence properties of the oxynitride particles with their local environment as well as to understand the growth mechanism. In this presentation, I will show the study of some oxynitride phosphors by means of low-energy cathodoluminescence.

  1. Xie R.-J. and Hirosaki N., Sci. Technol. Adv. Mat. 8, 588 (2007).


Dr. Benjamin Dierre, ICYS-MANA Researcher, MANA, NIMS


Dr. Kenjiro Miyano, Managing Director, ICYS, NIMS


Years of SAXS, the old and the new

Small-angle X-ray Scattering is old. First examples of the technique date back to the 1930's when the technique was in its infant stage. It could be said that the technique has (by now) passed "maturity" and went to the stage of "ripe old age". Anyone who has talked to a pensioner, though, knows that there is a lot of wisdom to be found in old age, and the literature on SAXS is replete with good examples, bad examples, and many trials-and-errors. This talk will start with a quick overview of small-angle scattering through the ages highlighting its rich history.

Now, though, we have what we need: good, reliable instrumentation with fairly problem-free detectors. Leveraging this, we can take small-angle scattering to the next level and obtain amazing amounts of bulk nanostructural details. In particular we are developing novel, robust analysis methods and applying them to a variety of real-world materials. The second half of this talk will highlight our efforts and progress in extracting nanostructural details from aligned and non-aligned structures through SAXS.


Dr. Brian Richard Pauw, ICYS-Sengen Researcher, NIMS


Dr. Kenji Sakurai, Group Leader, Quantum Beam Unit, NIMS