Time dependence of different contributions for the photovoltaic effect in ferroelectric PZT thin films with asymmetric electrodes

Abstract

In this work the photovoltaic response of ferroelectric Pb(Zr_0.20Ti_0.80)O₃ (PZT) thin films, with asymmetric Metal/Ferroelectric/Metal structure (Au/PZT/ITO), was investigated and its effect correlated to the ferroelectric and interface properties. We found two effects governing the photovoltaic response in these thin films, a depolarization electric-field (E_dep), dependent on the direction and magnitude of the polarization, and an internal built-in electric field (E_bi) which could be generated by the different electrodes and processing conditions. The time dependence of the photocurrent showed a strong reduction of the photocurrent after poling, probably related to a reaccommodation of charges and back-switching of the polarization, due to the rearrangement of the domain structure in the material.

KEYWORDS:

• Photovoltaic devices
• ferroelectric thin films
• domain structure
• functional interfaces

Acknowledgments

The authors would like to thank Mr. Francisco J. Picon, Mrs. Lais Conservan Nogueira and Mrs. Natalia Aparecida Zanardi for the technical support. We also thank professor Eudes Borges de Araújo for the fruitful discussion.

Additional information

Funding

This work was financially supported by CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico (Grants 163761/2017-5 and 421025/2016-6).