The present invention is a method and apparatus for receiving and converting incident radiation into DC current. The method begins with selection of an antenna having a terminal tip with a sharp edge. The antenna is layered with a substrate and a first coating. A first electrode and a metallic/mCNT antenna are layered on the first coating, and a plasmonic layer is then added. A gap is formed which is bounded on one side by the terminal ends of the plasmonic layer and the first coating, and a second electrode and a second coating on the other. The second electrode is layered upon the second coating which is layered upon the substrate. A set of AC currents is induced along the length of the antenna. The method then calculates whether or not the induced AC currents are large enough to create voltages for field emission. If the voltages are large enough, then a forward bias and a reverse bias are initiated. Due to the asymmetry in these tunneling barriers, a positive net DC current is delivered to an external circuit.