(a) Ferroelectric polarization loop (blue, left axis) and leakage current (red, right axis) of a Pt/PbTiO3(14 nm)/Nb:SrTiO3 junction measured with a conventional ferroelectric tester at 2 kHz. (b) Hysteresis loop of current generated by chopped laser light in the same sample, measured at a rate of 35 Hz between 1-second poling pulses with amplitudes ranging from −8 to +3 V.
Transient profiles of the heating laser power (a) and laser-induced currents from positively (b) and negatively (c) polarized Pt/PbTiO3/Nb:SrTiO3 junctions measured at 658 nm. The dotted line denotes the fitting results by the double exponential function for heating (red) and cooling (blue).
(a) Schematic illustration of fitting procedures during heating and cooling in order to split the pyroelectric and the photovoltaic currents. Hysteresis loops of photocurrent (b) and pyroelectric charge (c) measured during heating (left axis: blue downward triangle) and cooling (right axis: red upward triangle). The inset in (c) shows the difference between pyroelectric charges measured during heating and cooling.
I-V characteristics of a Pt/Nb:SrTiO3 junction in the dark (blue) and under laser illumination (red) at 658 nm. The inset shows the laser power dependence of the short-circuit current.
Saturated offset current from positively (filled symbols) and negatively (open symbols) polarized Pt/PbTiO3/Nb:SrTiO3 junction as a function of the laser power at 658 nm (red circle) and 1.06 μm (blue triangle). The inset shows the laser photon energy dependence of the photon yield from the positively (red circle) and negatively (blue triangle) polarized Pt/PbTiO3/Nb:SrTiO3 junctions.
I-V characteristics in the dark (blue circle) and under laser illumination (red triangle) at 658 nm (a) and 1.06 μm (b). Arrows show the voltage sweep direction. The inset in (a) shows the I-V characteristics for the opposite bias sweep direction. The inset in (b) shows expanded I-V data close to zero bias.
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