Controllable site occupation of Eu in intricate superstructure of perovskite Sr3Al2O6: Eu, Dy, Li to produce red luminescence

Abstract

An oxide red phosphor, with outstanding superiority in manufacturing cost, is particular desired for white light-emitting diodes (LEDs). In this work, a strategy to controllable site occupation of Eu in Sr3Al2O6 to give red light emission was employed with a three-step route: the combustion of sol–gel to prepare superfine precursor, the solid-sate reaction of precursor to incorporate Eu into small voids, and a second reduction in 25%H[Formula: see text]75%N2 atmosphere. Accordingly, a new red phosphor of Sr3Al2O6:Eu,Dy,Li was developed. The results shows the red luminescence of Sr3Al2O6:Eu could be improved by doping Dy[Formula: see text] and be further improved by co-doping Li[Formula: see text]. The red luminescence involves the [Formula: see text]-[Formula: see text] transition of Eu[Formula: see text] and the auto-ionization of electron from Eu[Formula: see text] to conduction band. Dy[Formula: see text] acts as a trap center of the thermally released electrons then with electrons returned to the 4[Formula: see text] ground state of Eu[Formula: see text], red light was emitted. The co-substitution of Sr[Formula: see text]–Sr[Formula: see text] by Dy[Formula: see text]–Li[Formula: see text] is helpful to balance defects and improve crystallization.