Assertion: semiconductor | /r/HasProperty | crystal
Facets:
Source sentences:
text: Most semiconductors are crystals made of certain materials, most commonly silicon.
text: Semiconductors are crystals that, in their pure state, are resistive (that is, their electrical properties lie between those of conductors and insulators) -- but when the proper impurities are added (this process is called doping) in trace amounts (often measured in parts per billion), display interesting and useful properties.