Can a material be electrically polarized with electromagnetic radiation? Is charge separation possible by bombardnment of electromagnetic radiation?
As conventional dielectric materials can be polarized with a electric field, I am wondering if electromagnetic radiation, which is composed itself of electric fields; could produce this effect.
 A: 
Can a material be electrically polarised with electromagnetic radiation?

Yes, this always happens when radio waves hit an electrical conductor.
Radio waves are a special case of EM radiation. By synchronously accelerating surface electrons back and forth on an antenna rod, they emit polarised photons.
If a receiving rod is now aligned in the same direction as the transmitting rod, then the jointly oscillating electric field of the photons that reach the rod moves surface electrons on the receiving rod.
Since there is also a jointly oscillating magnetic field of the photons, surface electrons can also be moved with a ring antenna (magnetic antenna).
Of course, such electric currents are generated in every piece of metal on which radio waves impinge. The antenna rod is just a part of the radio receiver with which the waves of a certain frequency are filtered out and electronically amplified.
A: Yes. A photodiode or a phototube does this.
When a sufficiently energetic photon is absorbed by an atom an electron is ejected from the atom. If this happens in air the electron will be stopped by air molecules and it is likely to fall back to the source, but in a vacuum it will have enough energy to leave and not return. In a suitable designed vacuum tube (a phototube), when light falls on one electrode it may be absorbed by another electrode in the vacuum tube, so there will be a voltage between the two electrodes in the tube.
Nowadays solid state photodiodes are used instead.
