[Celtman]

Uh..yeah, okay. Arsenic is used as a dopant for gallium based electronics but then the same is true for silicon.

      But in the case of gallium arsenide, the arsenic is a component of the pure (undoped) crystal.

[Dan Evans]

But in the case of gallium arsenide, the arsenic is a component of the pure (undoped) crystal.

Oh. I did not know that. So does that mean that after doping, both the p and n regions still have arsenic?