Processing and photoluminescence properties of surface crystallized ZnO glass-ceramics

ZnO surface crystallized glass-ceramics were fabricated using K2O-CaO-ZnO-B2O3-SiO2-Al2O3 glass system. Precipitation of Zn-containing oxide crystallites was affected by the chemical composition of borate glass, especially the amount of Al2O3. Substitution of SiO2 for B2O3 brought selective crystallization of ZnO without precipitation of α-Zn3B2O6. ZnO-precipitated glass-ceramics showed surface crystallization with submicron-sized crystallites, which assured transparency of these glass-ceramics. The obtained glass-ceramic shows free exciton emission, which is similar to emission of ZnO single crystal.