(under the class definition) Subject matter in which the device comprises plates of material each of which is coated with a layer of semiconductor material (e.g., copper oxide or selenium) which forms a rectifying barrier junction, the
device being made up of several flat conductive plates and semiconductor material layers to form a rectifier array.
(1) Note. Typical rectifiers of this type include (a) copper oxide rectifiers in which the rectifying barrier is a junction between metallic copper plate and cuprous oxide layer coated on one side of the plate and (b) selenium rectifier in which a thin layer of selenium is formed on one side of an aluminum plate with a highly conductive metal coated over the selenium. If the semiconductor material is specifically recited as selenium or tellurium, or an oxide of a metal such as copper oxide, the patent will be classified in the appropriate one of subclasses 42 or 43.
(2) Note. This type of device has generally been replaced with more modern devices, including silicon rectifiers.
