Photoluminescence Control and Superior Thermal Stability Enhancement in Eu2+-activated pollucite phosphors

In this work, two component substitution types of Si4+→[Cs+-Al3+] and [Mg2+-Mg2+]→[Cs+-Al3+] were successfully designed in Eu2+-doped CsAlSi2O6 pollucite phosphors. The photoluminescence color can be controllably tuned from cyan (513 nm) to blue (437 nm), and full width at half maximum (FWHM) can be adjusted in the region of 79–169 nm. Besides, the thermal stability is obviously improved, where PL intensity at 200 °C increases from 59% (CsAlSi2O6:5%Eu2+) of the original intensity to 96% [(CsAl)0.6Mg0.8Si2O6:5%Eu2+] and 86% [(CsAl)0.9Si2.1O6:5%Eu2+], respectively. The corresponding mechanisms of spectral adjustment and thermal stability enhancement were investigated. The proposed strategies can play a key role in exploiting novel and efficient phosphors for high-power w-LEDs lighting.