Structure and multicolor tunable luminescence based on Tb3+/Eu3+ doped La2W3O12 phosphors for white LEDs

Abstract

In this work, Tb3+ or Eu3+ single doped and co-doped La2W3O12 were synthesized via a solid-state reaction at 900 °C. The crystal structure and photoluminescence properties were systematically investigated in detail. It was found that the La2W3O12 based on the advantages of WO4 groups exhibits a broad absorption cross-section in the ultraviolet area, which can effectively enhance the emission intensity of Tb3+ and Eu3+. The energy transfer from Tb3+ to Eu3+ is determined by the dipole-dipole mechanism, and the energy transfer efficiency from Tb3+ to Eu3+ is as high as 36%. Based on efficient energy transfer effect, multicolor tunable emission from green to yellow and eventually toward red is realized. In addition, the temperature-dependent luminescence of La2W3O12: Tb3+, Eu3+ are carefully investigated, which suggested that as-prepared La2W3O12: Tb3+, Eu3+ phosphors are excellent candidates for solid-state laser, panel display, WLEDs and LED plant lights.