Abstract: An optoelectronic component with a photonic crystal, which also has an electronic band gap, and a method for controlling tunneling electron currents by means of photons are proposed. Essentially loss-free and very fast switching is enabled in that a photonic crystal has a defect mode in its photonic band gap for photons with such an energy that electron transitions, especially in the form of single-electron tunneling processes between adjacent ligand-stabilized metal clusters, can be induced by the irradiation of corresponding photons due to at least one defect site.