Nanocomposites and nanomaterials
Oxide nanostructured glass – ceramics luminescent composites for WLEDs
Nedilko S.G. 
Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv 01601, Ukraine. 
E-mail: SNedilko@univ.kiev.ua

Nowadays, white light-emitting diodes (WLED), as a new type of luminescent devices, due to their excellent properties have played an important crucial role in applications of indicator, backlight, automobile headlight, such as long lifetime, energy saving, environment-friendliness, small volume etc. It is common knowledge that major commercial diode is the phosphor converted LED made of blue-emitting chip and Y3Al5O12:Ce3+ dispersed in organic silicone binder. However, this binder in high-power device ages easily and become yellow colored due to accumulated heat emitted from chip, which strongly affects the device properties, and therefore reduces its long-term reliability and lifetime [1].
In this work we provide, first, a brief overview about recent progresses in developing transparent inorganic glass–ceramics phosphors excitable by near UV and blue chip LED. Second, we present the results of own study in this area. Three types of glass-ceramics nanostructured composites will be described. There are composites based on alkali-borate, phosphate - molybdates and vanadate – borate glasses. In accordance, suitable crystalline compounds of various types were used as micro/nanocrystalline component of glass-ceramics materials. There were some orthoborate (e.g., doped with RE ions Li6Gd(BO3)3,where RE = Eu), molybdate (doped with RE ions AIBIII(MoO4)2, where AI – alkali metal, BIII – Y, Bi, La, RE = Eu. Pr), and vanadates (La1-x-yEu(or Sm)yCaxVO4, e.g.) nanocrystals. 
Various experimental procedures were used to study structure, morphology and especially luminescent properties of noted composite systems. It is worth to note XRD, SEM, optical reflection, absorption, FTIR, and surely luminescent spectroscopy among them. 

1.	Daqin Chen, Weidong Xiang, Xiaojuan Liang, Jiasong Zhong, Hua Yu, Mingye Ding, Hongwei Lu, Zhenguo Ji. Advances in transparent glass–ceramic phosphors for white light-emitting diodes—A review // J. of European Ceramic Society.-2015.-35.-P. 859-869.