Photoluminescence properties and ultra-fast decay profiles of nanoparticles in sol–gel zirconia thin films xZrO2·100−x Cds : Mn2+ and Eu3+

Thin zirconia films doped with semiconductor nanocrystals xZrO2·100−x CdS : Mn2+ and Eu3+ (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 24–13×103 cm−1 is found to be composed of four spectral components due to band-edge emission (CdS), ligand to metal charge transfer (LMCT) center (ZrO2), surface-bound deep centers, and lattice-bound d–d (Mn2+) or f–f transition (Eu3+) centers. Luminescence of Mn2+ and Eu3+ 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.