Structural, morphological and up-converting luminescence characteristics of nanocrystalline Y2O3:Yb/Er powders obtained via spray pyrolysis

Sub-micronic, spherical Y2O3:Yb/Er particles comprising clustered nano-units (70 nm) were prepared via ultrasonic spray pyrolysis from pure nitrate precursor solutions with different Yb/Er dopant ratios. The particles were additionally thermally treated at 1100 degrees C for 12, 24 and 48 h. The structural and morphological characteristics of particles were studied by X-ray powder diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy dispersive X-ray analysis and specific surface area (BET) and were further correlated with their advanced optical properties. For the recorded up-conversion emissions, originating from the following Er3+ transitions: [H-2(9/2) - GT I-4(15/2)] in blue (407-420 nm); [H-2(11/2), S-4(3/2) - GT I-4(15/2)] green: 510-590 nm; and [F-4(9/2) - GT I-4(15/2)] in red (640-720 nm) spectral region, the corresponding lifetimes were acquired in the wide temperature range (10-300 K). The most intense green up-conversion emission with the long decay of 550 ms is recorded for Y1.97Yb0.02Er0.01O3 particles thermally treated at 1100 degrees C for 24 h. (c) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved