PHOTOVOLTAIC EFFECT BASED ON POLARIZATION CHARGE IN POLYCRYSTALLINE Pb(ZrTi)O₃ FILM

ABSTRACT

A steady-state short-circuit photocurrent across polycrystalline Pb(ZrTi)O₃(PZT) film is found to be directed opposite to ferroelectric polarization, defined by the magnitude of polarization, but it is not the depolarization current of the ferroelectric. To explain this, the authors assume that Pt/PZT/Ir capacitor consists of PZT grains and semiconductor PbO phase segregated on PZT grain boundaries and forming conducting channels. In such medium, uncompensated polarization charge can arise at the PZT/PbO interface and generate the electric field acting on carriers in PbO channels, thus producing the photocurrent across the film. The relation between the polarization charge and electric field is considered.

Keywords:

• polarization charge
• photovoltaic effect
• nondestructive readout

ACKNOWLEDGMENT

The study was supported by the RFBR, project No 06–08-01370-a and the Program of the RAS, project “Strong Correlated Electrons in Semiconductors, Metals, Superconductors and Magnetic Materials.”