Effect of shock compression on luminescence properties of CsAlSi2O6:Eu2+ for white-light-emitting diodes

Eu2+-doped CsAlSi2O6 (pollucite) phosphors were synthesized via high-temperature solid-state reaction to produce a white-light-emitting phosphor under UV irradiation. The obtained phosphors were characterized using X-ray diffraction, photoluminescence (PL), PL excitation, thermal stability, and PL decay. In contrast to previous reports, the fabricated phosphors emitted either white light or bluish white light with less thermal quenching and a higher internal-quantum efficiency (IQE) upon deep-UV excitation than upon near-UV excitation. The phosphors were subjected to shock compression at a pressure of 23 GPa to investigate the structural response of the pollucite. Although the pressure was higher than that required for a structural transition, no trace of a phase transition was observed. Although the chromaticity coordinates and thermal quenching of the shocked pollucite phosphors showed little change, a considerable degree of strain was induced and the PL intensity and IQE decreased due to a degradation in crystallinity. (C) 2016 Elsevier B.V. All rights reserved.