Studying edge losses in silicon heterojunction solar cells

In this manuscript we study the impact of edge losses in silicon heterojunction solar cells. The edge of the cells may play a larger role due to the large diffusion length of the carriers and the presence of a high conductive layer in this type of architecture. We fabricate silicon heterojunction solar cells with different areas and masking schemes to evaluate the impact of the edge on the open-circuit voltage. We measured lower open-circuit voltages on cells which have larger ratio of cell perimeter-to-area but have similar lifetimes and similar implied characteristics. The solar cell with 6 cm(2) shows open-circuit voltage 7 mV lower than the cell with 150.3 cm(2). Electroluminescence and photoluminescence imaging are used to evaluate the diffusion of carriers at the edges of the cells. We show the out diffusion of carriers at the edges of the cell which demonstrates the cell is affected by the surroundings.