Photoluminescent rare-earth based biphenolate lamellar nanostructures

A general nonaqueous route has been applied for the preparation of rare-earth ordered nanocrystalline hybrid structures. In a simple one-pot reaction process, Y3+ and Gd3+ isopropoxides were reacted in an autoclave with 4-biphenyl methanol at 275 degrees C. This approach leads to crystalline rare-earth oxide thin layers (similar to 0.6 nm) regularly separated from each other by organic layers of biphenolate molecules. The optical properties of these hybrid materials doped with Eu3+ and Nd3+, which are optical active lanthanides ions emitting in the red and near infrared, respectively, are presented. They show significant advantages compared to standard phosphors, such as higher radiance and luminance values, the possibility to tune the emission chromaticity by varying the excitation wavelength, and a much larger excitation range (250-350 nm and 300-500 nm for the Eu3+ and Nd3+ doped nanohybrids, respectively) shifted toward the red.