Multiple-Function Surface Engineering of SnO₂ Nanoparticles to Achieve Efficient Perovskite Solar Cells.

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Mismatched energy levels and interface defects between SnO2 electron transport layers (ETLs) and perovskite layers hinder perovskite solar cell (PSC) performance.
• Surface defects and poor charge transport at the ETL-perovskite interface are critical limitations in achieving high-efficiency PSCs.

Purpose of the Study:

• To develop a multifunctional surface engineering strategy for SnO2 nanoparticles to improve PSC efficiency.
• To address energy level misalignment and interface defects in PSCs through surface modification of the ETL.

Main Methods:

• Surface engineering of SnO2 nanoparticles using tetrabutylammonium (TBA+) and iodide (I-) ions.
• Fabrication of perovskite solar cells utilizing the modified SnO2 nanoparticles as the electron transport layer.
• Characterization of the modified SnO2 nanoparticles and the resulting solar cell performance.

Main Results:

• TBA+ ions enhanced SnO2 nanoparticle dispersion, stability, and interfacial charge transfer, suppressing recombination.
• I- ions passivated oxygen vacancies in SnO2 and halide vacancies in the perovskite layer.
• The modified SnO2 ETL (T-SnO2) achieved improved energy level alignment with the perovskite layer, reducing energy loss.
• The champion PSC based on T-SnO2 achieved a power conversion efficiency (PCE) of 21.71% with a high open-circuit voltage (VOC) of 1.15 V and negligible hysteresis.

Conclusions:

• Multifunctional surface engineering of SnO2 nanoparticles is an effective strategy to enhance PSC performance.
• The optimized ETL/perovskite interface leads to reduced charge recombination and improved device efficiency.
• This approach offers a promising pathway for developing high-performance and stable perovskite solar cells.