Broad band white-light-emitting Y5Si3O12N:Ce3+/Dy3+ oxonitridosilicate phosphors for solid state lighting applications

Highly thermostable white-emitting Ca9ZnK(PO4)7:Ce3+,Dy3+ single-phase phosphor with tunable photoluminescence and energy transfer

“…9,10 Therefore, to overcome these drawbacks, researchers have recently focused on developing single-phase white phosphor for the fabrication of WLEDs. 11,12 To obtain white light output from single-component phosphors, diverse strategies have been proposed, such as a hostsensitized method (host → Dy 3+ ); 13 single-doping of Eu 2+ , 14 Eu 3+ , 15 and Dy 3+ ions; 16 and co-doping of Ce 3+ /Dy 3+ , 17 Dy 3+ / Eu 3+ , 18 and Dy 3+ /Tm 3+ pairs. 19 In successful cases that have been reported, Dy 3+ activator plays an important role due to its intense transitions from 4 F 9/2 to 6 H 15/2 (blue) and 6 H 13/2 (yellow).…”

Single phase multi color emitting Ca2LuTaO6: Dy3+/Eu3+ double perovskite oxide phosphors

“…The trivalent Dy 3+ and Eu 3+ activated phosphors demonstrate their characteristics narrow band line emission in the blue to the yellow and white spectral region for Dy 3+ and orange to red emission for Eu 3+ doped in different host lattice phosphors 24‐26 . More interestingly, due to the 4 f 9 electronic configuration, which exhibits two dominant emission bands in the desired wavelength range of white light generation, the trivalent Dy 3+ ions are regarded as effective activators.…”

“…More interestingly, due to the 4 f 9 electronic configuration, which exhibits two dominant emission bands in the desired wavelength range of white light generation, the trivalent Dy 3+ ions are regarded as effective activators. More precisely, the Dy 3+ activated phosphors display a double emission band in the blue spectral region (470–500 nm), due to the magnetic dipole transition and in the yellow spectral region (570–600 nm) as a result of the electric dipole transition ( 4 F 9/2 → 6 H 15/2 ) 24,25 …”

“…The photoluminescence intensity of both the emission bands depends on the surrounding environment of the phosphors host lattice around the activated Dy 3+ ions 24,27 . Therefore by choosing the proper host materials to generate high‐ quality white light, the luminescence intensities of both the emission bands of the doped Dy 3+ ions will adjust the blue to yellow emission ratio (blue/yellow = 1) 24,25 . However, due to the highly shielded 4f electronic shell, Dy 3+ displays 4f – 4f spin forbidden transition, which is usually not favorable for the generation of highly efficient luminescence 28‐30 …”

“…Phosphors with double perovskite structure such as Sr 2 CaMoO 6 , BaLaMgNbO 6 , Sr 2 LaSbO 6 , LiLaMgWO 6 , and Sr 2 MgTeO 6 emerging a new promising candidate for the highly efficient narrow band line emission of these trivalent activators under the broad range of photoluminescence excitation, UV – blue light 42‐46 . Although phosphors with double perovskite structure proved themselves is excellent host materials for the highly efficient multicolor narrow band line emission attributed to the characteristics emission of these trivalent rare‐earth ions due to versatile crystal structure having high chemical and thermal stability with superior optical properties 2,24,47,48 . However, the concept behind the highly insensitive multicolor line emission of these rare‐earth‐doped ions in the double perovskite is still under investigation.…”