Synthesis and characterization of the novel color-tunable Eu/Tb(BPA)3phen composites

The new color-tunable luminescent Eu/Tb(BPA)3phen composites have been successfully fabricated by the solvothermal reactions. The characterization of the final products have been investigated by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TG-DSC) and Ultraviolet and visible (UV-Vis) spectrophotometer. It is found that the geometry of the composite particles is regular by scanning electron microscopy image. Thermogravimetric analysis indicates that the initial decomposition temperature of the final products is 334 °C, approximately. The results demonstrate that Eu/Tb(BPA)3phen composites have excellent thermal stability. And the products after decomposition are stable oxides (Eu2O3 and Tb2O3). Furthermore, Eu and Tb ions complexes exhibit strong red and green luminescence, respectively. Emitting color of physically blended Eu(BPA)3phen and Tb(BPA)3phen composites can be tuned in a wide range from red to yellow to green under the excitation of 350 nm single-wavelength ultraviolet light. The CIE coordinates of CTb, C1, C2, C3, C4, C5, C6 and CEu are calculated as (0.24, 0.60), (0.31, 0.56), (0.33, 0.55), (0.38, 0.52), (0.40, 0.51), (0.43, 0.48), (0.54, 0.41) and (0.65, 0.34), respectively. The color-tunable luminescent materials can be widely applications in many fields, such as the optical and electronic devices, fluorescent probe and labels.