Upconversion luminescence properties of Er 3+ in SrLaMgTaO 6 double perovskite phosphor

Abstract We report the properties of upconversion photoluminescence (UCPL) on SrLaMgTaO 6 crystal doped with trivalent erbium at concentrations of 1–20 mol% that were synthesized by a solid state reaction method from powder based precursors. The crystal structure, electronic structure, and optical properties of SrLa (1-x) MgTaO 6 :Er x were discussed by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), UV–vis spectrophotometer, DFT (density functional theory) calculations and photoluminescence (PL) spectra. Under the excitation of a 975 nm laser diode, the phosphors emitted green ( 2 H 11/2 , 4 S 3/2 → 2 I 15/2 ) and red ( 4 F 9/2 → 2 I 15/2 ) UCPL. Under the 10 mol% concentration of Er 3+ , the intensity of the green UCPL had increased in a linearly proportional to Er 3+ concentration, which was attributed to the UCPL of low concentration of Er 3 and it was mostly generated from ESA process. From higher Er 3+ concentration above 10 mol%, however, as the ETU process had additionally participated in UCPL the intensity of UCPL had decreased. It was attributed to the concentration quenching which was more active than ETU process at higher concentration of Er 3+ in SrLaMgTaO 6 .