  The ferroelectric polarization and short-circuit photocurrent in BaTiO3 thin
films have been studied for different contact configurations that allow to
measure the photoresponse and polarization under the presence of large or
negligible imprint field. It is found that in all cases, the direction of the
photocurrent is dictated by the depolarizing field and ultimately by the film
polarization, with a negligible contribution of the imprint electric field.
However, dramatic differences are found in their time-dependent photoresponse.
Whereas in presence of imprint, steady photocurrents are observed under
suitable illumination, transient photocurrents are generated in absence of
imprint. It is argued that this distinct behavior is determined by the
different Schottky barrier height at electrodes which thus offers a simple way
to tune the film photoresponse. These findings could be exploited for
electro-optic read-out and writing of ferroelectric memories.
