A novel narrow-band red-emitting multi-layer phosphor for white – Light emitting devices

Abstract

SrZr2La2O7: Eu+3 (0.5–2.5 mol %) phosphors have been synthesized through the standard solid-state reaction technique. The photoluminescent and other structural properties such as PXRD (Powder X-ray Diffraction), SEM (Scanning Electron Microscopy) and Energy Dispersive X-ray spectroscopy (EDX), FTIR (Fourier transform infrared spectroscopy), PSD (Particle Size Distribution) of the phosphors were learned. The photoluminescence spectra show that the phosphor exhibited intense and dominant red emissions at 627 nm belonging to the 5D0 → 7F2 electric dipole transition. The FWHM of the red emissions at 627 nm is only 8.0 nm increasing in luminous efficacy. Hereby we propose a novel RED phosphor for RED emitting LEDs with phosphor-embedded polymer matrix layers of variable thickness and stacking up to 400 µm. The intensity of the red color was enhanced by self-excitation of photon absorption and emission. As a result, Eu3+doped SrZr2La2O7 phosphors can be widely used as red phosphors in UV chip-based WLEDs and displays. The phosphor exhibits high color purity up to 99% when excited at 590 nm. X-ray powder diffraction analysis confirms that the phosphor is highly crystalline and has a cubic phase.