Optical properties of Mn4+-activated Na2SnF6 and Cs2SnF6 red phosphors

The effect of electron cloud expansion on the red luminescence of Sr4Al14O25:Mn4+ revealed by calculation of the Racah parameters

“…Moreover, the spectral configuration of Mn 4+ in the host of Sr 4 Al 14 O 25 significantly distinguishes from those reported in the K 2 TiF 6 [7], K 2 SiF 6 [7], Na 2 SnF 6 [8], Cs 2 SnF 6 [8], Na 2 SiF 6 [9], Na 2 GeF 6 [9], CaAl 12 O 19 [11], and YAlO 3 [15]. A broad band with doublet peaks are observed in the emission spectrum of Sr 4 Al 14 O 25 :Mn 4+ at room temperature, but several satellite peaks are observed in the others [7][8][9][10][11][12][13][14][15].…”

“…A broad band with doublet peaks are observed in the emission spectrum of Sr 4 Al 14 O 25 :Mn 4+ at room temperature, but several satellite peaks are observed in the others [7][8][9][10][11][12][13][14][15]. Besides the thermal vibration caused by the temperature, the spectral configuration is finally determined by the electronic effect and electro-magnetic interaction of the activator suffering from a certain crystal circumstance, depending on the symmetry of crystal site.…”

“…Recently, several researchers have focused on the development of new phosphors activated by Mn 4+ , such as the fluorides of K 2 TiF 6 :Mn 4+ [7], K 2 SiF 6 :Mn 4+ [7], Na 2 SnF 6 :Mn 4+ [8], Cs 2 SnF 6 :Mn 4+ [8], Na 2 SiF 6 :Mn 4+ [9], and Na 2 GeF 6 :Mn 4+ [9] as well as the aluminates of Sr 4 Al 14 O 25 :Mn 4+ [10], CaAl 12 O 19 :Mn 4+ [11], and the Mn 4+ activated non-stoichiometric 3SrOÁ5AL 2 O 3 [12]. A WLED device with high CRI (Ra 90), warm-white color temperature (3088 K), and an efficiency approximate 82 lm/W has been fabricated by the scientists in the GE Global Research Centre in New York, using the Mn 4+ activated red phosphor of K 2 TiF 6 :Mn 4+ [7].…”

Inorganic Phosphor Materials for Lighting

“…The investigation of this class of luminescent materials has been extended by the research group based at Gunma University in Japan, which has considered and investigated the hosts above, and several additional ones (Na 2 SnF 6 , Cs 2 SnF 6 , Cs 2 SiF 6 , Cs 2 GeF 6 , KNaSiF 6 ) doped with Mn 4? [177][178][179][180]. All these phosphors emit in the red region, and their synthesis, characterization and spectral properties have been reported.…”

Micronization of red-emitting K2SiF6:Mn4+ phosphor by pulsed laser irradiation in liquid

“…Recently, Adachi et al developed a direct chemical-synthesis technique for Mn-doped hexafluoride complex phosphors (A 2 XF 6 :Mn 4+ and BXF 6 :Mn 4+ , where A is an alkali metal; B = Ba and Zn; X = Si, Ge, Zr, Sn, and Ti) [19][20][21][22][23][24]. These phosphors exhibit efficient red emission (e.g., the PL quantum efficiency of K 2 SiF 6 :Mn 4+ is ∼0.4) under blue-light excitation.…”