Effects of WO3 dopant on the structure and electrical properties of Pb0.97La0.03(Zr0.52Ti0.48)O3 thin films

Pb 0.97 La 0.03 ( Zr 0.52 Ti 0.48 ) O 3 + x WO 3 at % (x=0, 0.2, 0.5, 1, and 2) (PLWZT) thin films are deposited on Pt–Ti–SiO2–Si substrates using a sol-gel process. We demonstrate that WO3 dopant plays a significant role on the structure and electrical properties of the PLWZT films. X-ray diffraction (XRD) analyses show that the PLWZT films undergo a dramatic tetragonal–to–cubic crystalline phase transformation with a small amount of WO3 additives. X-ray photoelectron spectroscopy (XPS) study shows that the chemical state of W changes with varying concentration of WO3 in the films. Moreover, PLWZT films with a small amount of WO3 doping (0.2 at %) show a decreased conductivity with an improved remnant polarization value of 30μC∕cm2. In addition, compared to the base (PLZT) film, such doping concentration also leads to significantly improved fatigue characteristics. A defect chemistry mechanism indicating the reduction of oxygen vacancies by the substitution of W for Ti at different doping concentrations has been proposed to explain the observed experimental results.