A Red‐Emitting La₄Ti₉O₂₄:Eu³⁺ Phosphor Excited by Multi‐Wavelength for Healthy Lighting

Abstract

Herein, an excellent red‐emitting La4Ti9O24:Eu3+ phosphor is produced using eco‐friendly hydrothermal and heat treatment techniques without a high‐temperature and multiple‐sintering process. The phosphor can be excited by multiwavelength light from 382 to 533 nm, and the three main characteristic emission peaks of Eu3+ ions are located at 592, 616, and 709 nm. Its decay time measured at 616 nm is calculated to be 3.32 ms. The color coordinates of La4Ti9O24:Eu3+ phosphor excited by 393 nm ultraviolet (UV) light are (0.665, 0.335), which are near to the Commission International de L'Eclairage (CIE) of red light (0.67, 0.33). A red light‐emitting diode was fabricated by the red‐emitting La4Ti9O24:Eu3+ phosphor encapsulating on a UV‐emitting chip (λ = 395 nm), eliminating the harmful effects of blue light on human eyes. Consequently, it would be a viable source of healthy illumination for display and lighting.