Two-dimensional simulation study of textured p-i-n a-Si:H solar cells with p-a-SiC:H and p-nc-Si:H window layers

Abstract In this paper two textured pin a-Si:H solar cells, one with an a-SiC:H p-layer and another one with a nc-Si:H p-layer are compared. The effect of varying: (i) p-doping concentration, (ii) dangling bonds density in i-layers, and (iii) the i-layer thickness, in the overall performance is studied using a realistic 2D model based on TCAD Sentaurus. Higher doping concentrations in p-layer increase the electric field in the absorber layer, while a low dangling bond density in the i-layer is desirable to reduce recombination. The effects of varying i-layer thickness are more complex. A compromise value of 400 nm obtained the best results. The structure with a nc-Si:H p-layer was found to be more stable when varying p-doping and it presents higher efficiencies in all simulated cases, mainly because of its higher optical absorption. Efficiencies up to 11.3% (for the nc-Si:H p-layer) and 11.2% (for the a-SiC:H window layer) were reached in the simulations, however, physical constraints should be taken into account in practice.

keywords: a-Si:H solar cellnc-Si:H window layera-SiC:H window layertextured2D simulation