Structure and optical properties of Mn2+ ions doped ZnO/Zn2SiO4 composite thin films

ZnO/Zn₂SiO₄ nanocomposite thin films doped with 1 mol% of Mn²⁺ ions were successfully synthesized by sol-gel spin coating method and subsequent thermal annealing in the ranges of 500–1000 °C. Effects of ZnO and SiO₂ molar ratio and annealing conditions, including one or two-step annealing, on the microstructure and PL properties of these thin films were investigated using X-ray diffraction, high-resolution transmission electron microscopy, UV–visible absorption spectroscopy, and emission spectroscopy. Results showed that precipitation of ZnO nanocrystals and willemite nanocrystals can be tailored by the composition and annealing conditions. Two-step annealing lead to more versatile modulation of the microstructure and dual band emission with blue from ZnO nanocrystals and green emission from Mn²⁺-doped Zn₂SiO₄ nanocrystals were achieved simultaneously, making these composite thin film materials promising for various optoelectronic applications.