Growth of SnO2 nanocrystals co-doped with Eu3+ for highly enhanced photoluminescence in mesoporous silica glasses

This study reports the growth of SnO2 nanocrystals (NCs) in mesoporous silica glasses and its great enhancement of Eu3+ photoluminescence at around 590 nm wavelength-band. Significantly different energy level character of Eu3+ was observed using photoluminescence (PL) spectra, which was attributed to the effect of the SnO2 crystal field. Remarkably, enhancement of Eu3+ as much as 116 times was achieved in the orange emission region by optimal SnO2 NCs addition. PL excitation spectra and decay curves verify the efficient energy transfer from SnO2 NCs to Eu3+. It is well understood that the highly enhanced emission originates from Eu3+ embedded in SnO2 NCs and the strong energy transfer between them. Our study has not only demonstrated an effective way to enhance down-conversion PL of rare earth ions in silica glasses, but also widened the applications of semiconductor oxides such as SnO2 NCs.