A novel narrow-band red-emitting phosphor for lighting and backlight display

White light-emitting diodes are prevalently used in indoor lighting due to their high efficiency, compactness, and environmental benefits. Stable narrow-band red-emitting devices are crucial for wide-color-gamut liquid crystal display backlights. To enhance the color rendering index of white LEDs and to realize wide-gamut backlight displays, a novel CaGdGaO₄:Eu²⁺ narrow band red-emitting phosphor was developed. This phosphor exhibits a red emission peak at 636 nm with a full width at half maximum of 58 nm under 470 nm light excitation. Additionally, it demonstrates high thermal stability (68.5%@423 K) and a good inner quantum efficiency of 48.9%. When integrated into white LED devices, it delivers a high color rendering index of 96.3 and a low correlated color temperature of 3854 K, achieving high-quality warm white illumination. Furthermore, a stable and bright red-emitting polydimethylsiloxane composite film was fabricated. A white LED backlight device with an expanded color gamut was also constructed using this phosphor as a red emitter, confirming its potential for high-quality backlight display applications.