Hetero-valent substitution design of high thermal stability reddish-orange Sr3Ga2Sn1·5Si2·5O14:Sm3+ phosphor for healthy lighting white-light-emitting-diodes applications

In this paper, a novel violet excited reddish-orange emitting Sr 3 Ga 2 Sn 1 · 5 Si 2 · 5 O 14 :Sm 3+ (SGSSO:Sm 3+ ) phosphor with high thermal stability was designed and synthesized by the high temperature solid state reaction method for the first time. The photoluminescence (PL) properties of the SGSSO:Sm 3+ phosphors were investigated systematically. Under 402 nm violet light excitation , SGSSO:Sm 3+ phosphor shows reddish-orange emission at 598 nm that is attributed to the 4 G 5/2  →  6 H 7/2 transition of the Sm 3+ ions. Importantly, the PL intensity of SGSSO:Sm 3+ at 423 K can maintain 87% of the initial value at room temperature . The high thermal stability of Sm 3+ in SGSSO was speculated to be attributed to the energy transfer mechanism of trap formed by the hetero-valent substitution of Sm 3+ at Sr 2+ sites. Finally, a WLED has been fabricated by combing the violet LED chip with the as-prepared reddish-orange emitting phosphor , commercial blue BaMgAl 10 O 17 :Eu 2+ (BAM:Eu 2+ ) and green (Ba,Sr) 2 SiO 4 :Eu 2+ ((Ba,Sr)S:Eu 2+ ) phosphors. The results indicated that the as-prepared SGSSO:Sm 3+ phosphor can be a potential candidate of the reddish-orange component for violet chip pumped white-light-emitting-diodes.