Description
Flexible crystalline silicon (c-Si) solar cells offer a promising route toward lightweight, wearable, and portable photovoltaic (PV) technologies. However, achieving high performance through low-temperature, cost-effective fabrication remains a significant challenge. This work demonstrates a novel hybrid solar cell (HSC) architecture by integrating light-trapping silicon nanowires (SiNWs) with a low-temperature organic/inorganic heterojunction formed between n-type c-Si and p-type PEDOT. The approach enables efficient junction formation while preserving the mechanical flexibility of ultra-thin Si substrates.
Flexible 50 μm c-Si substrates were fabricated by alkali etching of conventional 200 μm Si wafers. Random SiNWs were synthesized via a rapid room-temperature metal-assisted chemical etching (MACE) process using AgNO₃/HF, followed by Ag removal using NH₄OH/H₂O₂ treatment. A PEDOT/2-propanol solution containing 7 wt% ethylene glycol was subsequently spin-coated onto the SiNW surface, followed by annealing and electrode deposition to fabricate Ag/PEDOT:PSS/SiNW-Si/In:Ga hybrid solar cells.
The SiNW architecture dramatically suppressed broadband (400–1100 nm) optical reflection from ~27% for planar Si to ~8%, significantly enhancing light harvesting. Consequently, the short-circuit current density (Jsc) increased from 20.40 mA cm⁻² for planar thick HSCs to 24.05 mA cm⁻² for thin-flexible and 25.93 mA cm⁻² for thick SiNW-based HSCs. Power conversion efficiencies of 9.00% and 10.26% were achieved for thin-flexible and thick SiNW devices, respectively, substantially outperforming their planar counterparts (6.59% and 4.52%). The enhanced PV performance was further corroborated through morphological characterization, optical measurements, minority carrier lifetime analysis, dark current characteristics, and external quantum efficiency.
These findings establish a scalable, low-temperature strategy for fabricating efficient flexible c-Si HSC, demonstrating the synergistic benefits of SiNW-induced light management and organic heterojunction engineering. The proposed design opens a promising avenue towards next-generation lightweight, mechanically compliant, and high-performance photovoltaic technologies for emerging flexible energy applications.
| I am the presenting author | Yes |
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