- A rectifier which utilizes one or more metal disks coated with a semiconductor layer. This layer may consist of selenium, copper oxide, or another suitable semiconductor. The rectification occurs as a result of the greater conductivity across the contact in one direction than the other. Also called metallic-disk rectifier, dry rectifier, dry-disk rectifier, or contact rectifier.
- A rectifier consisting of, or incorporating, semiconductor materials. An example is a diode rectifier.