The large spontaneous polarization can serve as a knob to engineer the photoresponse. Read the attached papers

Although the photocurrent originates from the built-in electric field formed by electric dipoles, the larger Ps is not the main factor that induces larger photocurrent, because the gap is another key factor for the carriers’formation. Smaller band gap usually corresponds to smaller exciton bonding energy, thus leading to larger photocurrent under the same solar illumination.

The photocurrent could be largely enhanced if the polarized direction of the monochromatic light is perpendicular to the spontaneous polarization direction.

Chandra Bhal Singh Thank you so much. so if we tune the bandgap and create a strong electrical field by spontaneous polarization, then we have a larger photocurrent