Characterization of green-emitting translucent zinc oxide ceramics prepared via spark plasma sintering

Translucent, green-emitting zinc oxide (ZnO) bodies, 19 mm in diameter and 0.72 mm in thickness, have been prepared via spark plasma sintering method. The consolidation of ZnO powders was investigated over the temperature range of 550-1050°C and the pressure range of 55-530 MPa. Samples sintered at temperatures >850°C and pressures of ∼120 MPa were translucent and had densities of ∼100%. Samples sintered at 950°C and 130 MPa showed a higher maximum transmittance than the samples sintered at higher or lower temperatures or pressures, with an excellent in-line transmission of 70% in the IR region around 2330 nm. The dense ZnO ceramics exhibited a strong green emission and a weak ultraviolet emission, and the relative intensity of the green emission increased with increasing sintering temperature.