Luminescent properties of LaKNaTaO5 and rare-earth-doped LaKNaTaO5 synthesized by an improved hydroxide melt method

Single crystals of LaKNaTaO5 is facilely obtained in corundum crucible at 600 °C by adding a certain amount of water to the hydroxide flux of KOH/NaOH additionally, which is a green method to avoid the heavy metal silver pollution compared with the silver tuber. The addition of water plays a critical role in the reaction process by changing the auto-dissociation of OH− in hydroxide melts. In addition, we have synthesized samples doped with Eu3+ and Tb3+ by the same route respectively and have investigated the effects of concentration and temperature on the photoluminescence (PL) properties. The results demonstrate that rare-earth-doped LaKNaTaO5 is an ideal material for white light emitting diodes (WLEDs).