Structure, Luminescence, and Energy Transfer of a Narrow-Band Green-Emitting Phosphor Ce₅Si₃O₁₂N:Tb³⁺ for Near-Ultraviolet Light-Emitting Diode-Driven Liquid-Crystal Display

The exploration of narrow-emitting phosphors in the red, green, and blue spectral region is of great significance for improving the color gamut of liquid-crystal displays (LCD). In this work, a narrow-band green-emitting phosphor Ce5Si3O12N:Tb3+ matched with a near-ultraviolet chip was successfully synthesized by a solid reaction process. The crystal structure, luminescence, and energy transfer of Ce5Si3O12N:Tb3+ were investigated in detail. Interestingly, Ce5Si3O12N has self-luminescent properties, and its excitation falls in the near-ultraviolet region and emits a broad band cyan light, which belongs to the 5d–4f transition of Ce3+ ions. Through the energy transfer between Ce3+ and Tb3+, Ce5Si3O12N:Tb3+ can be effectively excited by a near-ultraviolet light and electron beam and emits a narrow-band green light with a maximum at 545 nm. The energy transition efficiency can reach 53.9%, but the thermal stability of Ce5Si3O12N:Tb3+ is worse. The results show that Tb3+-activated Ce–Si–O–N compounds are potential narrow-band green phosphors for LCD applications.