In science communicator Steve Mould's Youtube video Why all solar panels are secretly LEDs, he supplies a voltage across a solar cell. Using an IR camera, we see IR emission coming from the solar cell, and he claims that is LED behavior.
Is it not more likely that the IR we're seeing is blackbody radiation? My understanding of LEDs is that indirect semiconductors (i.e. silicon) make for terrible light-emitters, and the energy will be emitted non-radiatively by a phonon.