Field-effect passivation for minimized voltage loss in highly efficient antimony selenosulfide solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Semiconductor Physics

Background:

• Antimony selenosulfide (Sb2(S,Se)3) solar cells suffer from low power conversion efficiency (PCE) due to poor heterojunction quality and interface recombination.
• Significant open-circuit voltage (VOC) losses are observed at the buffer/absorber interface, hindering device performance.

Purpose of the Study:

• To develop a field-effect passivation strategy to enhance the performance of Sb2(S,Se)3 solar cells.
• To mitigate interface recombination and reduce open-circuit voltage (VOC) loss.

Main Methods:

• Introduction of a low-work-function tantalum pentoxide (Ta2O5) dielectric layer between CdS and Sb2(S,Se)3 layers.
• Utilizing Ta2O5 as a substrate for growing highly crystalline Sb2(S,Se)3 films.
• Leveraging positive fixed charges in Ta2O5 to enhance built-in electric field and charge transport.

Main Results:

• Achieved a record power conversion efficiency (PCE) of 10.95% (10.65% certified) for Sb2(S,Se)3 solar cells.
• Obtained a high open-circuit voltage (VOC) of 695 mV, indicating a significantly reduced voltage deficit.
• Demonstrated suppression of non-radiative recombination probabilities through enhanced electron extraction and reduced hole accumulation.

Conclusions:

• The Ta2O5 passivation strategy effectively optimizes interface quality and mitigates VOC loss in Sb2(S,Se)3 photovoltaics.
• This approach establishes a universal physical passivation paradigm for high-performance solar cell development.
• The findings pave the way for advancing Sb2(S,Se)3-based solar cell technology.