Investigation of the mechanism responsible for the photoluminescence enhancement with Li + co-doping in highly thermally stable white-emitting Sr8ZnSc(PO4)7:Dy3+ phosphor

The strategy of co-doping Li+ was used with the aim of enhancing the emission intensities of Sr(Z8)nSc (PO4)(7) under near ultraviolet excitation. The luminescence enhancement was related to the deep defects V-o(..) which were produced by the introduction of ion. Furthermore, much deep V-o(..) were produced with the incorporation amount Li+ ion increasing. As the sensitizer, the produced deep V-o(..) can effectively tunnelling transfer energy to the nearby activator Dy3+ resulting in the photoluminescence enhancement in SZSPO:1.5%Dy3+,5%Li+ In addition, its yellow/blue emitting ratio and photo luminescent quantum yields both were improved under longer wavelength excitation. Furthermore, the excellent thermal stability of optimal SZSPO:1.5%Dy3+,5%Li+ excelled over commercial phosphor DS-200 below 225 degrees C. The electroluminescence properties of fabricated ABPD-WLED reach the optimum with V=10 V and 1=800 mA (lambda(ex)=365 nm) or 700 mA (lambda(ex)=388 nm), then the bright white luminescence can be obviously observed. These photoluminescence, electroluminescence and thermal properties testified the potential application of Sr8ZnSc(PO4)(7):1.5%Dy3+,5%Li+ as a new-style warm-white emitting LEDs phosphor. (C) 2017 Elsevier B.V. All rights reserved.