EFFECT OF INVERSION ON THE GRAIN-BOUNDARY POTENTIAL OF A POLYCRYSTALLINE SEMICONDUCTOR

The potential barrier at a semiconductor grain boundary is studied considering an inversion layer at the interface between the two grains. The predicted values of the barrier height are found to be considerably different from those obtained using a conventional model based on depletion approximation. It is found that, once the inversion layer is formed, the potential barrier does not change appreciably with the density of the localized states. A critical value of the density of states above which an inversion layer may be formed at the interface is obtained. Both monoenergetic and continuous energy distribution of localized states are considered for the estimation of the potential barrier. Approximate expressions for grain boundary potential are derived for strongly inverted grains. The barrier height values obtained from approximate relations are found to be very close to those obtained numerically.