string: germanium URL: https://www.flickr.com/people/germanium/ publication date: 27 August 2006 described at URL: https://www.flickr.com/photos/germanium/226329066/
Point-contact diode effect takes place in the germanium surface just below the wire tip. The other wire connect to the germanium surface. English Wikimedia username:
string: germanium URL: https://www.flickr.com/people/germanium/ publication date: 16 July 2006 described at URL: https://www.flickr.com/photos/germanium/190916639/
string: germanium URL: https://www.flickr.com/people/germanium/ publication date: 12 March 2007 described at URL: https://www.flickr.com/photos/germanium/419197317/