Effect of deep levels on semiconductor carrier concentrations in the case of "strong" compensation

We analyze the carrier concentrations (≡p) resulting from both shallow and deep majority levels. We show that for comparable concentrations of shallow and of compensating levels, a small fraction of deep levels can decrease p by orders of magnitude. Also, a quantitative criterion for obtaining semi-insulating material is derived, and implications for obtaining conducting wide-band-gap materials are discussed. Another result: a steep ("deep") slope of lnp vs 1/T can result even from small percentages of deep levels.