Photoluminescence properties and ultra-fast decay profiles of nanoparticles in sol–gel zirconia thin films xZrO 2·100− x Cds : Mn 2+ and Eu 3+

Abstract

Thin zirconia films doped with semiconductor nanocrystals xZrO 2·100− x CdS : Mn 2+ and Eu 3+ ( x=20, 50, 80) were prepared by sol–gel method to classify emission centers by measurements of luminescence, time-resolved luminescence, excitation spectra and decay profiles in the temperature range between 10 and 300 K. The broad emission band over the 24–13×10 3 cm −1 is found to be composed of four spectral components due to band-edge emission (CdS), ligand to metal charge transfer (LMCT) center (ZrO 2), surface-bound deep centers, and lattice-bound d–d (Mn 2+) or f–f transition (Eu 3+) centers. Luminescence of Mn 2+ and Eu 3+ showed x-composition-dependent spectral profiles and shortening of lifetimes to 5–50 μs at 10 K. Ultra-fast decay components of 0.5–1.5 ns were also detected in thin films at room temperature. Luminescence properties of doped-CdS nanocrystals are characterized by dependence on annealing temperatures, very fast decay times and low thermal activation energy of 1300 cm −1 in comparison with bulk crystals.