Silica Zinc Titanate Wide Bandgap Semiconductor Nanocrystallites: Synthesis and Characterization
A. M. Mansour, Ali B. Abou Hammad, Ahmed M. Bakr, Amany M. El Nahrawy
Abstract
Abstract SiO 2 x:ZnO: (1-x)TiO 2 nanocrystallites were made via sol-gel route, and co-firing at a lower temperature (600 o C). The synthesized nanocrystallites were characterized using several analytical techniques including XRD, SEM/TEM, FT IR, THz, and UV–visible spectroscopy analysis. The results appear that the silicate phase was used to promote the density of the nanocrystalline ceramic during calcination. The lower temperature calcined (∼600 o C) nanocrystallites consist of ZnTiO 3 , Zn 2 SiO 4 , and TiO 2 phases, with ZnTiO 3 dominant rhombohedral phase, showing various electronic transitions. The obvious electronic properties give 2.8 eV as indirect bandgap transition and 3.35 ± 0.01 eV as direct bandgap transition with the increase of silica content. The dielectric constant is in the range 8 at a frequency higher than 10 4 Hz due to the formation of Zn 2 SiO 4 , and the ac conductivity is in the range 10 − 10 to 10 − 7 S/cm.