Na0.2La0.2Sr1.6WO6:Mn4+: An efficient far-red-emitting phosphor via a cation-pair partial substitution
Xinyue Liu, Youzhen Shi, Kang Cheng, Xinyong Gong, Weichao Huang, Chaoyong Deng
Abstract
A novel far-red emitting phosphor Na 0.2 La 0.2 Sr 1.6 MgWO 6 : Mn 4+ can be fabricated by high-temperature solid-state reaction. Photoluminescence excitation and photoluminescence spectra of this phosphor were analyzed in detail. Effective far-red light peaking at 691 nm was observed when the phosphors were excited by 350 nm or 467 nm. By using a [Na + -La 3+ ] unit substituting [Sr 2+ -Sr 2+ ] unit partially, the far-red emission intensity of Sr 2 MgWO 6 :0.006Mn 4+ can be improved about 60.5 times. Moreover, it exhibited a high thermal stability; the value of I 373K / I 298K was approximately 46.59% of that at room temperature . Finally, there are a broad spectral overlap between the emission band of Na 0.2 La 0.2 Sr 1.6 MgWO 6 : Mn 4+ phosphors and the absorption band of phytochrome P FR under near-ultraviolet light spectrum. Therefore, the obtained phosphors Na 0.2 La 0.2 Sr 1.6 MgWO 6 : Mn 4+ have potential to be a new type far-red luminescent powder for indoor plant growth LEDs.