Synthesis And Studies On LaAlO₃/YAG Phosphors Doped With Rare Earth Ions

The application of Rare Earth Luminescent Materials has been the focus in high-tech fields, such as lighting, display, messaging and so on. Upconversion luminescence materials can change infrared photons into visible light, while quantum cutting light materials can absorb high-energy photons and release double or more low-energy photons, so the former has a great prospect in bio-detection and the later may raise energy efficiency.Aluminates substrate phosphors had attracted a lot of attention because of their excellent chemical, thermal stability and highly absorption of ultraviolet and vacuum ultraviolet photons. YAG, whose molecular formula is YAl5O12 has been a good laser and seintillator matrix, while LaAlO>3 has not received enough attention although its structure is similar to YAG.The research include the following contents:1. LaAlO3 matrix was prepared by co-precipitation method. The effect on the performance and size of crystals was studied in different reaction conditions. X-ray diffraction and SEM showed that higher temperature and longer reaction time would improve the crystallization properties of LaAlO3, but the higher temperature would increase the particle size, inducing reunion.2. The luminescence properties of Tb3+doped in LaAlO3matrix has been studied. Spectral on room temperature showed that the luminescence intensity increased with increasing concentration when the Tb3+doping concentration was less than 1% and opposite when the concentration was more than 1%. Higher temperature and longer reaction time would enhance Tb3+luminescence intensity.3. We studied the energy transfer between Tb3+ and Yb3+ ion in LaAlO3 matrix. When the samples was excited by light in 980nm the up-conversion process would occur, indicating the two-photon process. When the light was changed to 193nm, down-conversion would occur. The energy transfer from Gd3+ toTb3+ in matrix was observed, sensitizing Tb3+ions.4. Preparation and Characterization of a YAG/Pr3+, Eu3+ system helped the understanding of the energy transfer between Pr3+ and Eu3+.