Achievement of well conducting wide band-gap semiconductors: Role of solubility and of nonequilibrium impurity incorporation

A long-standing problem for wide band-gap semiconductors is that of achieving good bipolar conductivity. I here show that this difficulty can be understood via solubility considerations of dopant incorporation. Reports of good conductivity in such materials are likely due to nonequilibrium impurity incorporation, and prior literature is reinterpreted to provide examples of this view.