Effect of structure development on self-trapped exciton emission of TiO2 thin films

Photoluminescence of thin crystalline TiO2 films was studied. The films contained an anatase phase and were grown by the atomic layer deposition method on different single crystal substrates. A polarised re-combination emission of self-trapped excitons was observed in the films at 5 K. A comparison of the obtained spectra with those of the single crystal anatase allowed determining crystallite orientations in the films. Results were consistent with the X-ray diffraction and reflection high-energy electron diffraction data.