Stability of photovoltage and trap of light-induced charges in ferroelectric W O3 -doped (Pb0.97 La0.03) (Zr0.52 Ti0.48) O3 thin films

Abstract

The stability of photovoltage in W O3 -doped (Pb0.97 La0.03) (Zr0.52 Ti0.48) O3 (PLWZT) ferroelectric thin films was investigated. For in-plane polarized configuration, with a greatly enhanced electrode gap, the reduction ratio of photovoltage during multicycle UV illumination was significantly smaller and stability of photovoltage was greatly improved over the sandwich capacitor configuration. The ferroelectric-metal interfacial effects including Schottky barriers and polarization screening due to the trap of photoinduced charges at interfaces were found to determine the magnitude, stability, and even the polarity of the photovoltage, particularly for the electrode-sandwiched PLWZT thin films. © 2007 American Institute of Physics.