Upconversion photoluminescence of ZrO2:Er3+ nanocrystals synthesized by using butadinol as high boiling point solvent

Erbium doped ZrO2 (ZrO2:Er3+) nanocrystals are prepared by a butadinol low thermal crystallization method. The crystallization temperature is reduced to 500 °C. X-ray diffraction (XRD) spectra show there exists monoclinic and cubic ZrO2 phases. Green, yellow and red lights are seen from the upconverting luminescence spectra under 980 nm excitation. The results confirm that upconverting emission is due to excited-state absorption (ESA) and energy transfer upconverting (ETU) process.