Hydrothermal synthesis and luminescence properties of octahedral LiYbF4: Er3+ microcrystals

LiYbF4: Er3+ octahedral microcrystals have been successfully prepared through a facile hydrothermal method assisted with EDTA (ethylenediaminetetraacetic acid). X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric and differential scanning calorimeters (TG-DSC), photoluminescence (PL) spectra are used to characterize the samples. Under 976 nm excitation, the upconversion (UC) luminescence emission spectra of LiYbF4: Er3+ microcrystals show the characteristic Er3+ emissions. The results show that the infrared light emissions at 792 nm of I-4(9/2) -> I-4(15/2) are dominantly strong unusually, while the green emissions at 526 and 545 nm assigned to H-2(11/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2), respectively, and the red emission at 667 nm of F-4(9/2) -> I-4(15/2) are relatively weaker. Most importantly, the samples show more efficient luminescence with further heat treatment. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.