Up-converting characteristics of Y203:Yb/Er nanocrystalline powders obtained through spray pyrolysis

Sub-micronic, spherical Y203:Yb/Er particles comprising clustered nano-units were prepared through ultrasonic spray pyrolysis of pure nitrate precursor solutions that contain different Yb/Er dopants ratio (10, 5 and 2). The particles obtained were additionally heat-treated at 1100°C for 12, 24 and 48 hours. Detailed structural and morphological analyses were done through X-ray powder diffraction (XRPD), scanning and transmission electron microscopy (SEM/TEM), specific surface area (BET), particle size distribution (LPS) and Fourier Transform Infrared Spectroscopy (FTIR). Obtained results are further correlated with advanced powder optical properties confirmed by efficient up-conversion emissions of Er3+in: blue (407-420 nm, 2H9/2→4I15/2), green (510-590 nm, 2H11/2, 4S3/2→4I15/2) and red (640-720 nm, 4F9/2→4I15/2) spectra. The corresponding lifetimes in the function of temperature will be also presented and discussed