EN
A solar cell (indium tin oxide (ITO)/p-doped amorphous silicon (p-a-Si:H)/intrinsic polymorphous silicon (i-pm-Si:H)/n-doped crystalline silicon (n-c-Si)) simulation, focused on p-layer doping density NA and surface band bending E_{sbb} at the interface ITO/p-layer has been performed. Despite the deterioration of p-layer material quality with doping density, the reduced bulk recombination was found to compensate for the increased loss in the p-layer. An increase of p-layer doping density NA and contact barrier height φ_{b0} (variation of the surface band bending E_{sbb}) leads to an increase of the efficiency of heterojunction with intrinsic thin layer solar cells.