The Effect of Annealing on the Optoelectronic Properties and Energy State of Amorphous Pyrochlore Y2Ti2O7 Thin Layers by Sol-Gel Synthesis

Pyrochlore titanate (Y2Ti2O7) is a promising material for a wide range of applications in optoelectronics and photocatalysis due to its advantageous chemical, mechanical, and optical properties. To enhance its potential for such uses, however, a high-quality and scalable synthesis method is required. We here investigate the crystallization of sol-gel produced Y2Ti2O7 layers. We observe a transition of the amorphous pyrochlore phase at annealing temperatures below 700 degrees C. The transmittances of the Y2Ti2O7 thin layers annealed at 400 to 700 degrees C are approximately 92.3%. The refractive indices and packing densities of Y2Ti2O7 thin layers annealed at 400-700 degrees C/1 h vary from 1.931 to 1.954 and 0.835 to 0.846, respectively. The optical bandgap energies of Y2Ti2O7 thin layers annealed at 400-700 degrees C/1 h reduce from 4.356 to 4.319 eV because of the Moss-Burstein effect. These good electronic and optical properties make Y2Ti2O7 thin layers a promising host material for many potential applications.

Automated summary

This study investigates the crystallization and optical properties of sol-gel produced Y2Ti2O7 thin layers. The results show a transition of the amorphous pyrochlore phase at annealing temperatures below 700 degrees C. The annealed Y2Ti2O7 thin layers exhibit high transmittance and varying refractive indices, packing densities, and optical bandgap energies.