> But diamond semiconductors are much too expensive ATM. It is also difficult to dope diamond n-type, as most of the donors are not shallow. Interestingly: Th

> But diamond semiconductors are much too expensive ATM. It is also difficult to dope diamond n-type, as most of the donors are not shallow. Interestingly: The conduction band in bulk diamond is above the vacuum level, meaning that conduction electrons "want" to fall out of the material. (Surface physics gets in the way.)