Boundary conditions at grain boundaries

Grain boundaries in polycrystalline semiconductor material are frequently idealized as surfaces possessing a characteristic surface recombination velocity. Minority carrier densities generated by external sources (electron beams, light, etc.) in polycrystalline p--n junctions must satisfy certain boundary conditions at these grain boundaries which will be derived. It will also be shown that a ''folding technique'' introduced recently to deal with this problem is of limited value