A thermally stable narrow-band green-emitting phosphor MgAl 2 O 4 :Mn 2+ for wide color gamut backlight display application

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 7; no. 27; pp. 8192 - 8198
• Main Authors: Song, E. H., Zhou, Y. Y., Wei, Y., Han, X. X., Tao, Z. R., Qiu, R. L., Xia, Z. G., Zhang, Q. Y.
• Format: Journal Article
• Language: English
• Published: 11.07.2019
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/C9TC02107H

The discovery of stable narrow-band green emitting phosphor suitable for blue InGaN chip excitation is crucial to improve the color gamut of the phosphor converted backlighting device. However, it is a great challenge. Herein, a Mn 2+ activated thermally stable narrow-band green emitting phosphor MgAl 2 O 4 :Mn 2+ peaking at 525 nm with a full-width at half-maximum (FWHM) of 35 nm and a quantum efficiency of 45% upon 450 nm blue-light excitation is demonstrated. This phosphor does not exhibit thermal quenching even up to 300 °C (109.5%@300 °C of the integrated emission intensity at 23 °C) due to the high rigidity of the host MgAl 2 O 4 . Using the as-synthesized optimized phosphor Mg 0.95 Al 2 O 4 :0.05Mn 2+ as the green light component, and a commercial phosphor K 2 SiF 6 :Mn 4+ as the red one, an InGaN chip excited white LED device with a color gamut of 116% National Television System Committee (NTSC) standard is obtained. Furthermore, by applying the fabricated LED device for backlights in a liquid crystal display (LCD) TV, a more colorful frame can be realized compared to when commercial LED backlights are used, suggesting that the Mn 2+ ion based green emitting phosphor has great potential for application as LCD backlights.