Synthesis of cobalt oxide Co3O4 doped zinc silicate based glass-ceramic derived for LED applications

In this research, the fabrication of willemite based glass-ceramics doped cobalt oxide (Co3O4) are successfully derived from ZnO-SiO2 glass system by using melt-quenching technique and controlled heat treatment process. The physical, structural and optical properties were measured by using electronic densitometer, X-Ray diffraction, Fourier Transform Infrared, absorption spectroscopy and Photoluminescence spectroscopy. The densities of the samples are increase with increase of heat treatment temperature due to the increase in crystallinity and structure rearrangement of the samples. The crystallinity of the Co-doped samples started at 800 degrees C and alpha-Zn2SiO4 peak positions can be observe after heat treated at 900 degrees C while in FTIR spectra showing all typical band around 510 and 580 cm(-1) indicating the formation of ZnO-SiO2 bonding phase. Besides, the transition for Co2+ ions had been found from (4)A(2) -> T-4(1) and from the analysis optical band gap of Co-doped samples are decreasing with increasing of heat treatment temperature. Co2+ doped Zn2SiO4 revealed a red emission at 717 nm.