DEPOSITION AND CHARACTERIZATION OF PHOTOCONDUCTIVE PZT THIN-FILMS

Deposition by the aqueous acetate solution (DAAS) technique was used t o synthesize highly crystalline thin films of undoped and 2% iron-dope d Pb(Zr0.53Ti0.47)O-3 [PZT(53,47)] perovskites on sapphire and Pt subs trates at 600 degrees C. Fe ions were added either at the precursor st age or diffused thermally. The crystallization of the films was measur ed by x-rag; diffraction. The ferroelectric activity was examined by p olarization voltage hysteresis (P-E) loops. The electro-optical proper ties of ferroelectric/photoconductive PZT thin films were investigated by excitation photocurrent spectroscopy (EPS) and 77 K emission spect roscopy. The photoconductivity measured at visible wavelengths was enh anced for the thermally diffused, but not the precursor-processed dope d materials. This, together with lattice parameters obtained from x-ra y data and P-E hysteresis loop measurements, suggested that the precur sor-processed doped ions are strongly bonded in the perovskite lattice , whereas the thermally diffused ions are bound more weakly in the gra in boundaries.