Preface to the Focus Issue on Novel Applications of Luminescent Optical Materials

This focus issue of the ECS Journal of Solid State Science and Technology (JSS) complements our previous focus issue (JSS, Vol. 2, No. 2, 2013) in that the current issue provides a comprehensive picture of the progress in the area of luminescent materials and processes. This volume contains both review and research articles. The aim of the review articles has been to acquaint the readership with current state-of-the art research and development in luminescent and optical materials. We hope that they will serve as reference materials for researchers and graduate students entering this challenging area. We have expanded the scope of this issue to include topics on biological applications of luminescent materials, recent advances in organic light-emitting devices (OLED), scintillators, nano-phosphors, and quantum dots in addition to phosphors for solid state lighting and display applications. In view of the rapid advancements in the area of novel phosphor systems for solid state lighting, we have explored not only the material issues but also the current status of theory of luminescence processes. Emphasis has been on transition metal and rare earth ions to demonstrate recent advancements in theory to predict or describe the excited state processes, including non-radiative transitions in luminescent materials. The scope of future research in the area of novel phosphors for application in III-V LEDs for general lighting has been delineated. Another area of research which is dealt with extensively in this issue pertains to the current status of OLED research activities. Novel