Crystal structure, electronic structure and photoluminescence properties of KLaMgWO6:Eu3+ phosphors

Abstract

A variety of Eu3+-activated KLaMgWO6 phosphors were synthesized by a traditional high temperature solid state reaction method in air atmosphere. By using geometric optimization and Rietveld analysis, the detailed structural properties were derived for the first time. The band structure, electronic distribution and phonon dispersion were calculated using the plane-wave density functional theory (DFT). Meanwhile, the optical band gap of KLaMgWO6 host was measured with an ultraviolet-visible diffuse reflection spectroscopy (UV–vis DRS). The charge transfer band (CTB) of KLaMgWO6:Eu3+ phosphors is situated at ultraviolet and near-ultraviolet region from 250 to 410 nm. Combined with theoretical calculations and experimental results, the detailed luminescence process is deduced. The phosphors show intense absorption in near ultraviolet-blue region and exhibit strong red emissions with CIE coordinates of (x = 0.6474, y = 0.3360) under 344 and 394 nm excitation. Excellent luminescence properties make it have potential application in the fabrication of white light-emitting diodes (LEDs).