Nanostructured rare earth doped Nb2O5: Structural, optical properties and their correlation with photonic applications

In the present work, we report on a systematic study on structural and spectroscopic properties Eu3+ and Er3+-doped Nb2O5 prepared by sol-gel method. The Eu3+ ions were used as structural probe to determine the symmetry sites occupied by lanthanide ions. The Eu3+-doped Nb2O5 nanocrystalline powders were annealed at different temperatures to verify how the different Nb2O5 crystalline phases affect the structure and the luminescence properties. Er3+-doped Nb2O5 was prepared showing an intense NIR luminescence, and, visible luminescence on the green and red, deriving from upconversion process. The synthetized materials can find widespread applicability in photonics as red luminophor for white LED (with tricolor), optical amplifiers and upconverter materials.