Structure and luminescence investigation of Gd3+-sensitized perovskite CaLa4Ti4O15:Eu3+: A novel red-emitting phosphor for high-performance white light-emitting diodes and plants lighting

A novel perovskite CaLa4Ti4O15:Eu3+ red-emitting phosphor was synthesized via a sol-combustion method, and Gd3+ was further co-doped into structure to improve the luminescence performance. The effects of Eu3+ doping and Gd3+ co-doping concentrations on the microstructure and luminescence properties were investigated. The red emission peaks of as-prepared phosphors originate from the 5D0→7Fj electron transitions of Eu3+ ions. Under 273 nm excitation, the luminescence intensity of Eu3+ was significantly enhanced through the energy transfer between Gd3+ and Eu3+ in CaLa4Ti4O15, and the luminescence intensity was also improved even under the excitation of 394 nm. By combining red-emitting CaLa4Ti4O15:Eu3+, Gd3+ phosphor with commercial blue and green phosphors on n-UV chip (λ = 395 nm), an eye-friendly w-LEDs with appropriate correlated color temperature (4761 K) and high color rendering index (Ra = 93.1) has been realized. The electroluminescence spectrum of the packaged red LED have an excellent match with the PR absorption of plants. In addition, when introducing CaLa4Ti4O15:Eu3+, Gd3+ phosphor into a commercial w-LED with YAG:Ce3+, the adjustable chromaticity parameters like CCT and CRI values can be obtained. These results demonstrated that the as-prepared CaLa4Ti4O15:Eu3+, Gd3+ phosphor is an outstanding candidate as the red component for the application of w-LEDs and plants lighting.