Novel approach for fabrication of buried contact silicon nanowire solar cells with improved performance

Generally, a selective SiNW-type structure is used to avoid resistive loss in SiNW-based solar cells. However, the performance of these selective SiNW-based solar cells is lower than that of conventional Si solar cells, due to their low collection efficiency and high series resistance. Herein, a novel process is developed to enhance the collection efficiency of photogenerated charge carriers, and hence the performance of SiNW solar cells. Self-aligned single-step lithography is used to fabricate buried contact SiNW (SiNWBC) solar cells. The effectiveness of the SiNWBCs is manifested in the conversion efficiency (η ≈ 15.02%) of the solar cell, which is improved by ∼7.82% compared to that of the control selective SiNW cell (η ≈ 13.93%). The performance and PV cell parameters of the SiNWBCs are analyzed and compared with those of this control cell. Losses due to the PV cell parameters of the SiNWBC solar cell are lower than those of the control cell. The reduced number of front surface recombinations lowers the n and J₀ values, resulting in enhanced SiNWBC cell performance.