Well-OrganizedSingle White-Emitting GdMoBO₆:Eu³⁺, Tb³⁺, Dy³⁺/Bi³⁺ Phosphors Enabled by the EnergyTransfer Process for White LED-BasedIndoor Lighting

In recent years, single white-emitting phosphors and their optical properties have attracted extensive worldwide attention. Aiming at this fact, a series of near-UV excitable Tb³⁺, Eu³⁺, and Bi³⁺/ Dy³⁺-codoped GdMoBO₆ phosphors were developed. Under UV excitations, individual Eu³⁺ and Tb³⁺-activated GdMoBO₆ phosphors exhibit exceptional red and green emissions due to Tb³⁺ (⁵D₄ → ⁷F_<i>J</i>=3–6) and Eu³⁺ (⁵D₀ → ⁷F_<i>J</i>=1–4) transitions. The tunable color tone (green to yellowish white) has been obtained in Eu³⁺ and Tb³⁺-codoped GdMoBO₆ phosphors due to the sensitizing effects of the self-activated host, and the energy transfer process from Tb³⁺ ions to Eu³⁺ ions. Additionally, Dy³⁺/Bi³⁺ ions were included in the optimized Eu³⁺-Tb³⁺-codoped system to enhance the photoluminescence further via the sensitizing effect of the Dy³⁺/Bi³⁺ ions. When combined with a 370 nm UV LED chip, the Gd_0.573MoBO₆:0.04Tb³⁺, 0.007Eu³⁺, 0.02Dy³⁺ system exhibited white light emission with a color rendering index (Ra) of ∼87 and a correlated color temperature of ∼4960 K. Whereas, Gd_0.573MoBO₆:0.04Tb³⁺, 0.007Eu³⁺, 0.02Bi³⁺ showed a white light emission with a color rendering index (Ra) of 81 and a correlated color temperature of 5114 K. These optimized single-component white-emitting phosphors have potential for white LED-based lighting applications.