Photoluminescence and electrical properties of highly transparent (Bi,Eu)4Ti3O12 ferroelectric thin films on indium-tin-oxide-coated glass substrates

Highly transparent (Bi,Eu)(4)Ti3O12 (BEuT) ferroelectric thin films were prepared on indium-tin-oxide (ITO)-coated glass substrates by using chemical solution deposition technique, and the photoluminescence and electrical properties of the thin films were investigated in terms of annealing temperature and concentration of europium ions. The BEuT thin films had a polycrystalline bismuth-layered perovskite structure and exhibited excellent optical transmittance. Photoluminescence spectra of the thin films included two strong peaks which originated from two transitions of D-5(0)-> F-7(1) (594 nm) and D-5(0)-> F-7(2) (617 nm). The emission intensity of two peaks increases with increasing annealing temperature due to improved crystallinity of the thin films. An unusual composition quenching effect of photoluminescence was found in the rare earth doped bismuth titanate thin films. In addition, the BEuT thin films also showed ferroelectric properties comparable to those of BEuT thin films deposited on Pt/Ti/SiO2/Si substrates. These results suggest that BEuT thin films can be considered as a promising multifunctional material which can find applications in transparent optoelectronic devices. (C) 2008 American Institute of Physics.