Preparation And Photoluminescence Properties Of Tm³⁺/Eu³⁺ Doped Glass Ceramics Containing Zno Nanocrvstals

Combining the advantage of crystal and glass, glass ceramics have excellent physical and chemical properties, thermal stability and optical homogeneity, thus can be widely used in lighting, display, laser and other optoelectronic materials and devices. On the other hand, ZnO nanomaterials with outstanding optoelectronic characteristics have broad potential applications in the field of advanced functional materials. In this thesis, the rare earth ions doped glass ceramics containing ZnO nanocrystals were fabricated by melt-quenching method followed by heat treatment.Using the differential thermal analysis, X-ray diffraction, transmission electron microscopy, Fourier infrared spectrum, absorption-transmission spectra, and photoluminescence spectra, the effects of raw material composition, heat treatment condition, rare earth ions and excitation wavelengths on the preparation and photoluminescence properties of glass ceramics were investigated systematically. The main results were listed as following:With the decrease of ZnO/K2O or SiO2/ZnO ratio and the increase of the Al2O3/ZnO ratio, glass ceramics containging ZnO nanocrystals produce more easily.Glass ceramics containging ZnO nanocrystals have a photoluminescence band from 450 nm to 750 nm with amaximum at ?580 nm. With the shorter-time or lower-temperature heat treatment, glass ceramics have stronger emission intensity,which is resulted from the imperfections of ZnO nanocrystals with smaller size and subsequent more crystal defects. With the increasing heat treatment time or temperature, the crystal defects decrease, thus the emission intensity of glass ceramics containing ZnO nanocrystals decrease gradully.After heat treated at 750 ? for 5 min, Tm3+ doped glass ceramics containing ZnO nanocrystals show a narrow emission peak located at 453 nm and a wide emission band at 580 nm under 360 nm excitation, which are attibuted to the 1D2?3F4 transition of Tm3+ and the defect emission of ZnO nanocrystals, respectively. By adjusting the excitation wavelength and the concentration of Tm3+, glass ceramics with blue, white and orange-yellow light emitting properties are obtained. The chromaticity coordinate of Tm3+ doped glass ceramic with white light emitting properties is (0.33,0.32).After heat treated at 730? for 5 min,Eu3+ doped glass ceramics containing ZnO nanocrystals show a wide emission band at 550 nm and a narrow emission peak at 612 nm under 325 nm excitation, which is attibuted to the energy transfer from the ZnO nanocrytals to Eu3+. With increasing concentration of Eu3+, the emission intensty of Eu3+ increases while the emisison intensity of ZnO nanocrystals decreases, thus the energy transfer efficiency increases gradully...