Synthesis and photoluminescence properties of a novel double perovskite NaGdMgTeO6:Sm3+red-emitting phosphor for plant growth LEDs and w-LEDs

This research used solid-state reaction methods to synthesize a series of double perovskite structure NaGdMg-TeO6:xSm3+ (x = 0.5-30 mol%) phosphors. A systematic study was conducted on the crystal structure, phase purity, photoluminescence (PL) properties, concentration quenching mechanism, color purity, thermal stability, and inner quantum efficiency (IQE) of the samples. Under 405 nm excitation, NaGdMgTeO6:Sm3+ phosphors showed strong red emission at 648 nm, attributed to the 4G5/2 & RARR; 6H9/2 transition of Sm3+ ions. The optimal luminescence intensity was achieved at the dopant concentration of 1 mol%, and the dipole-dipole interaction mechanism contributed to the concentration quenching process. High color purity of more than 99.8% and appropriate Commission International de L'Eclairage (CIE) chromaticity coordinates were obtained for the NaGdMgTeO6:Sm3+ phosphors. High thermal stability and activation energy (Ea = 0.293 eV) were found to be excellent characteristics of the phosphors. Ultimately, the fabricated red LED in this study revealed superior spectral matching with the phytochrome Pr. The white light-emitting diode (w-LED) prepared had a high color rendering index (Ra) of 90 and a suitable correlated color temperature (CCT) of 5337 K. As a result, these phosphors are potentially suitable for use in plant growth LEDs and w-LEDs.

Automated summary

This research synthesized a series of NaGdMg-TeO6:xSm3+ phosphors with a double perovskite structure using solid-state reaction methods. The crystal structure, phase purity, photoluminescence properties, concentration quenching mechanism, color purity, thermal stability, and inner quantum efficiency of the samples were systematically studied. The NaGdMgTeO6:Sm3+ phosphors exhibited strong red emission at 648 nm under 405 nm excitation, with the optimal luminescence intensity achieved at a dopant concentration of 1 mol%. The phosphors showed high color purity, thermal stability, and activation energy. The fabricated red LED showed superior spectral matching with Phytochrome Pr, and the w-LED had a high color rendering index and a suitable correlated color temperature. These phosphors have potential applications in plant growth LEDs and w-LEDs.