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

• A new approach is investigated for buried contact SiNW solar cell fabrication.
• Single-step photolithography is used for self-aligned buried contact formation.
• Cell efficiency is improved to 15.02% (buried contact) from 13.93% (control).
• Reduction in recombination and resistive losses are observed in SiNWBC solar cell.
• IQE enhancement of SiNWBC solar cell is observed for λ < 600 nm.

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.

A new approach was investigated for the self-aligned fabrication of buried contact SiNW (SiNWBC) solar cells via single-step photolithography. The effectiveness of the buried contact manifests in the conversion efficiency (η ≈ 15.02%) of the solar cell, for which there is a relative improvement of ∼7.82% compared to that of the control cell (η ≈ 13.93%). The Jsc of this cell is increased by enhancements in both the light absorption and collection efficiency. The performance and PV cell parameters of the SiNWBC cell are analyzed and compared with those of control cell. Loss because of the PV cell parameters in the SiNWBC cell is lower than that in the control cell. The reduction in front surface recombination contributes to reducing the values of n and J0 for the SiNWBC cell.Figure optionsDownload as PowerPoint slide