Diode quality factor in polycrystalline solar cells

The increase in diode quality factor with decreasing grain size in polycrystalline conductor (metal or degenerate semiconductor)‐insulator‐semiconductor (MIS) solar cells is explained as due to (1) an increase in insulator‐semiconductor interface charge due to the presence of grain boundaries on the I‐S surface, and (2) the voltage drop at the grain boundaries in the polycrystalline base semiconductor.