Multicolor properties and applications of Ln3+ doped hierarchical NaY(WO4)2via a facile solvothermal process
Up to now, research on the synthesis of Ln3+-doped NaY(WO4)2 nanocrystallites has been mostly focused on the traditional preparation routes such as the hydrothermal method followed by calcination at high temperature or the molten salt method. However, the products obtained through these methods are usually large in size and the procedures are laborious. With the development of optoelectronic devices, there is an urgent need to find an efficient method to prepare NaY(WO4)2:Ln3+ with good crystallinity and stronger emission properties. In this work, we demonstrate a simple, fast and reproducible solvothermal strategy to synthesise NaY(WO4)2 with hierarchical structure. Furthermore, Tb3+ and Eu3+ ion co-doped NaY(WO4)2 phosphors were also prepared, and various emission colors were obtained. The energy transfer between the Tb3+ and Eu3+ ions in the NaY(WO4)2 host matrix has also been demonstrated. Finally, a highly efficient and stable NaY(WO4)2:0.05Tb,0.06Eu based W-LED device was built. The tunable multicolour emission, ease of preparation and hierarchical structure reveal that NaY(WO4)2:Ln3+ crystals have potential application in full color displays and W-LEDs.