Narrow-Band Red-Emitting Phosphors with High Color Purity, Trifling Thermal and Concentration Quenching for Hybrid White LEDs and Li 3 Y 3 BaSr(MoO 4 ) 8 :Sm 3+ , Eu 3+ -Based Deep-Red LEDs for Plant Growth Applications.

Trivalent europium-based monochromatic red light-emitting phosphors are an essential component to realize high-performance smart lighting devices; however, the concentration and thermal quenching restrict their usage. Here, we report a series of efficient Eu 3+ -substituted Li 3 Y 3 BaSr(MoO 4 ) 8 red-emitting phosphors based on a stratified scheelite structure with negligible concentration and thermal quenching. All of the host and phosphor compositions crystallize in monoclinic crystal structure (space group C 2/ c ). All of the phosphor compositions produce narrow-band red emission (FWHM ∼6 nm), which is highly apparent to the human eyes, and lead to exceptional chromatic saturation of the red spectral window. Concurrently, detailed investigations were carried out to comprehend the concentration and thermal quenching mechanism. Absolute quantum yields as high as 88.5% were obtained for Li 3 Y 0.3 Eu 2.7 BaSr(MoO 4 ) 8 phosphor with virtuous thermal stability (at 400 K, retaining 87% of its emission intensity). The light-emitting diodes were constructed by coupling Li 3 BaSrY 0.3 Eu 2.7 (MoO 4 ) 8 red phosphor with a near-UV LED chip (395 nm) operated at 20 mA forward bias, and the hybrid white LED (an organic yellow dye + red Li 3 Y 3 BaSr(MoO 4 ) 8 :Eu 3+ phosphor integrated with an NUV LED chip) showed a low CCT (6645 K), high CRI (83) values, and CIE values of x = 0.303; y = 0.368, which indicated that the synthesized phosphors can be a suitable red component for white LEDs. In addition, we have systematically investigated the Sm 3+ and Sm 3+ , Eu 3+ activation in Li 3 Y 3 BaSr(MoO 4 ) 8 to display the latent use of the system in plant growth applications and establish that the phosphor exhibits orange red emission with an intense deep-red emission (645 nm ( 4 G 5/2 → 6 H 9/2 )). The phytochrome (Pr) absorption spectrum well matched the fabricated deep-red LED (by integrating a NUV LED + Li 3 Y 3 BaSr(MoO 4 ) 8 :Sm 3+ and Eu 3+ phosphor) spectral lines.