Tunable Single‐Phase White Light Emission from Complex Perovskite Sr<sub>3</sub>CaNb<sub>2</sub>O<sub>9</sub>: Dy<sup>3+</sup>/Eu<sup>3+</sup> Phosphors
Noor Zamin Khan, Sayed Ali Khan, Nisar Muhammad, Weilong Chen, Jahangeer Ahmed, Muhammad Amin Padhiar, Mei Chen, Marcin Runowski, Saad M. Alshehri, Baohua Zhang, Shusheng Pan, Ren‐Kui Zheng
Abstract
Abstract Sr 3 CaNb 2 O 9 :Dy 3+ /Eu 3+ phosphors with a complex perovskite structure are prepared using a high‐temperature solid‐ state reaction technique. These phosphors are doped either singly or in combination with Dy 3+ /Eu 3+ ions, resulting in efficient energy transfer from Dy 3+ to Eu 3+ and thus tunable‐color emission. Under 353 nm excitation, the Sr 3 CaNb 2 O 9 :Dy 3+ phosphor emits blue (492 nm), yellow (583 nm), and red (682 nm) light, with the optimal doping concentration of Dy 3+ of 0.04%. When excited by 394 nm ( 7 F 0 → 5 L 6 ), the Sr 3 CaNb 2 O 9 :Eu 3+ phosphor exhibits two most intense emissions centered at 593 nm ( 5 D 0 → 7 F 1 ) and 614 nm ( 5 D 0 → 7 F 2 ). The decrease in luminescence intensity with increasing doping concentration of Dy 3+ and Eu 3+ is due to the cross‐relaxation associated with electric dipole–dipole interaction. Photoluminescence emission measurements under excitations of 353 and 365 nm indicate that the Sr 3 CaNb 2 O 9 :0.04Dy 3+ /0.05Eu 3+ phosphor shows excellent thermal stability, even at a temperature of 150 °C, where the luminescence intensity preserves 79% of its initial value at room temperature. The electroluminescence performance of the Sr 3 CaNb 2 O 9 :0.04Dy 3+ /0.05Eu 3+ phosphor is tested with 365 nm LED chips for potential use in white LEDs. The results confirm that Sr 3 CaNb 2 O 9 :0.04Dy 3+ /0.05Eu 3+ phosphor has great potential for use in high‐power white LED applications as a single matrix.