ESTIMATION OF THE EFFECTIVE DIELECTRIC RESPONSE FROM HOPPING ACTIVATION ENERGY IN THE VICINITY OF INSULATOR-METAL TRANSITION IN SEMICONDUCTORS

Abstract

The effect of the energy overlap integral, due to the partial overlap of the adjacent wave functions of impurities, on the dielectric response ε of n-type semiconductor is examined. The proposed model suggests that ε diverges as the overlap increases, i.e. as the impurity concentration n is increased and essentially goes to a non-vanishing value as n approaches a critical value nc, defining the insulator-metal transition. It also predicts that ε→k (the host material dielectric constant) when n becomes low enough such that the impurity contribution to ε is negligibly small.