Boron, arsenic, and antimony, among other substances, are used as dopants when added to a pure semiconductor material to alter its electrical characteristics.
Artificially produced gemstones[?] (such as Ruby (gemstone)) usually contain a dopant to identify them as such.
... York City, Woolley was a professor and lecturer at Yale University (one of his students was Thornton Wilder) who began acting on Broadway in 1936.
He was typecast as the ...