Photoluminescence from electrodeposited zinc oxide films modified with Eu ions

The photoluminesecence (PL) of porous ZnO films modified with Eu(3+) ions was studied. The samples were fabricated by electrodeposition using eosin Y (EY) dye molecules. Scanning electron microscopy images and X-ray diffraction patterns showed that the porous films have nanometer-scale networks and become finer with increasing EY concentration. Sharp PL peaks due to the intra-4f transitions of Eu(3+) ions were clearly observed. The PL peak intensity was higher in finer porous films. The temperature dependence and decay profiles of the PL intensity indicated that capping Eu(3+) ions with 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (TTA) were effective for enhancing PL intensity. Furthermore, PL excitation spectra were observed and the excitation of Eu(3+) ions was discussed.