Preparation and luminescent properties investigation of red and near-infrared emitting Mn4+, Ln3+-doped Al-based nano-fluoride phosphors 

Novel Mn4+,Ln3+-doped (Ln3+ = Eu3+,Dy3+,Tb3+,Sm3+,Yb3+,Er3+,Tm3+,Ho3+) Al-based with alkali metal, alkali earth metal or rare earth elements nano-fluorides will be prepared using a hydrothermal method. The emission positions will locate at red region based on the occupancies of Al3+ sites by Mn4+ and different regions for Ln3+ sites by alkali earth metal or rare earth elements originated from close ionic radius between them. Owing to the unbalance of charge, the effects to photoluminescence properties of additions of different charge compensating impurities will be investigated. Besides, the effect of source of fluoride will be supplied. Moreover, the asprepared phosphors will match photoluminescence excitation and emission spectra, and thermal stability with YAG. The final objective is to obtain good w-LEDs with better color rendering index and lower correlated color temperature.