Temperature Dependence of Mn4+ Emission Intensity and Lifetime in TriGain® Phosphor (K2SiF6:Mn4+)

The temperature dependence of the Mn 4+ photoluminescence and lifetime has been measured in the red emitting K 2 SiF 6 :Mn 4+ phosphor that is sold under the trade name, TriGain ® . In the range 12−450 K, the 2 E → 4 A 2 emission intensity increases considerably while the lifetime decreases. Above 450 K, rapid decrease in the intensity and lifetime is observed. The results are interpreted in terms of dynamically induced increases in the emission intensity and decay rate coupled with an Arrhenius-type thermal quenching. The parameters of our fitting to physical models are compared with those reported on laboratory synthesized K 2 SiF 6 :Mn 4+ phosphor. This comparative study sheds light on factors responsible for non-radiative relaxation processes, which is fundamental to the understanding of phosphor quantum efficiency and performance. The temperature dependence of the Stokes to anti-Stokes vibronic line intensity ratios is also measured and analyzed. Due to low thermal conductivity of K 2 SiF 6 , it was necessary to develop protocols to ensure that the surface temperature of the phosphor was close to that of the cold finger in the closed cycle He cryostat.