Effect of nonuniform carrier distribution on average resistivity: Case of polysilicon grains

Abstract

Grain boundaries of polycrystalline semiconductor film trap free carriers creating space charge regions. The length of the depleted regions depends on the trapping states density and free carriers concentration within the grains. As the carrier concentration within depletion region is lower the resistance there can is higher than in the rest of the grain. It is shown that the average concentration of free carriers and specific resistivity can be significantly different from that obtained for the case of uniform free carrier distribution in the grain.