Electronic transport in random media: examples for nanocrystalline and amorphous silicon films

Randomly distributed grain boundaries and/or random potentials dominate the electronic transport in random media. An effective medium or percolation approach is shown to be useful for understanding electronic transport for nanocrystalline and amorphous silicon films. It is shown that any transport problem in 3-dimensional (3D) random media can be reduced to 1D problem by the percolation argument. We find a universal feature of electronic transport in random media