  The out-of-plane and in-plane polarization of
(Pb0.6Li0.2Bi0.2)(Zr0.2Ti0.8)O3(PLBZT) thin film has studied in the dark and
under illumination of a weak light source of a comparable bandgap. A highly
oriented PLBZT thin film was grown on LaNiO3 (LNO)/LaAlO3(LAO) substrate by
pulsed laser deposition system which illustrates well-saturated polarization
and its significant enhancement under illumination of light. We have employed
two configurations for polarization characterization; first deals with out of
plane polarization with single capacitor under investigation, whereas second
demonstrates the two capacitors connected in series via the bottom electrode.
Two different configurations were illuminated using different energy sources
and their effects were studied. The latter configuration shows a significant
change in polarization under illumination of light that may provide an extra
degree of freedom for device miniaturization. The polarization was also tested
using positive-up & negative-down (PUND) measurements which confirm robust
polarization and their switching under illumination.
