IV.2 - Selenium and Copper Oxide diodes?

Cuprous-oxide-on-copper rectifiers were first used for the rectification of large currents in 1924. Selenium rectifiers were used extensively before Si power technology was sufficiently developed, due to its relatively simple manufacturing. Selenium was also used in solar cells and photoresistors. Selenium typically has a knee voltage of 0.5V, and copper oxide has a knee of 0.2V. Both have relatively linear forward I-V curves. Apparently the large-area sandwich structure of selenium rectifiers provides for excellent heat sinking capabilities. Also, they are supposed to be quite robust as far as tolerating excessive currents is concerned.

• Edal Industries Inc, 4 Short Beach Road, East Haven, CT 06512
  Phone (203) 467-2591
  Fax (203) 469-5928
  

  Edal manufactures a range of high-voltage silicon diodes, as well as selenium and copper oxide diodes.