V. Kiisk *، نويسنده , , I. Sildos، نويسنده , , S. Lange، نويسنده , , V. Reedo، نويسنده , , T. Ta¨tte، نويسنده , , M. Kirm، نويسنده , , J. Aarik، نويسنده ,
Photoluminescence (PL) of pure and Sm3+-doped TiO2, ZrO2 and HfO2 thin films were studied in the temperature range of 6–
300 K. The thin (100–250 nm) films were prepared by using both the atomic layer deposition (ALD) technique and the sol–gel
spin-coating process. The ion implantation was applied to dope the ALD-grown films with Sm3+ ions, whereas an in situ doping
was used in the sol–gel process.
The PL was excited via band-to-band transitions by using several pulsed lasers as well as tuneable synchrotron radiation in
the energy range of 4–20 eV. PL excitation spectra and decay kinetics were recorded.
The dominating intrinsic emission of undoped materials was attributed to the radiative recombination of self-trapped
excitons (STE). In doped materials, a broadband emission superposed by Sm3+ emission lines of a well-pronounced fine
structure was observed under laser excitation. The broadband emission was attributed to the recombination of various bound
The PL excitation spectra of doped and undoped films showed different behaviour, which was attributed to the damage
produced by ion implantation and uncontrolled impurities incorporated into the films in sol–gel process.
Relaxation of electronic excitations and the energy transfer process to Sm3+ ions is discussed.