A geometric diode, method and device applications are described. The geometric diode is produced including a device body formed from an electrically conductive material having an equilibrium mobile charge density, and having a device surface configuration. The material has a charge carrier mean free path with a mean free path length and the device body size is selected based on said the free path length to serve as an electrically conductive path between first and second electrodes delimited by the device surface configuration that is asymmetric with respect to a forward flow of current in a forward direction from the first electrode to the second electrode as compared to a reverse current flow in an reverse direction from the second electrode to the first electrode. A system includes an antenna for receiving electromagnetic radiation coupled with the geometric diode antenna to receive the electromagnetic radiation to produce an electrical response.