The way I read it the process still conforms to Kirchoff’s law (current in = sum of current from each load out). It’s the law of conservation of energy that is in question. Apparently, with the photons and electrons as output there appears to be more energy out than in.
See #9. The conservation law applies to the charge, not current, becuase the current increases at the junction, because of the application of the external field. Since the current out does not equal the current in for this device, consesrvation of energy needs to be used. The charge carriers in this device are being accelerated at the junction. That is why the currents aren't equal.