In a p-n junction photo cell, the value of the photo-electromotive force produced by monochromatic light is proportional to

the voltage applied at the p-n junction the barrier voltage at the p-n junction the intensity of the light falling on the cell the frequency of the light falling on the cell

the intensity of the light falling on the cell

Electromotive force depends upon intensity of light falling, it does not depend on frequency of barrier voltage.