Europium(II) Activated Blue–Cyan Aluminosilicate Phosphors with Zero Thermal Quenching

The ″cyan gap″ is the bottleneck of full-visible-spectrum white light-emitting diodes (WLEDs), and the development of high thermal stability blue-cyan phosphors plays a decisive role in compensating for the cyan gap. Herein, we report a blue-cyan-emitting celsian phosphor prepared using Ba²⁺-doped LTA/FAUX zeolite. Excited by UV light, celsian phosphors show a super broad emission at the blue-cyan range with a full width at half-maximum (fwhm) more than 100 nm, the broadband emission effectively eliminates the cyan gap and has excellent thermal quenching resistance (120% @ 25 °C). A full-visible-spectrum WLED device prepared using the phosphor exhibits a color rendering index as high as 93, exhibiting great advantages in WLEDs. These studies not only show great promise of celsian phosphor as a blue-cyan emitter but also open the way for the preparation of suitable phosphors in zeolite materials.