Stabilizing SnO₂ Colloids via Phosphate Buffering for Efficient and Durable Perovskite Photovoltaics

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Tin oxide (SnO2) nanoparticles are crucial for electron transport layers in perovskite solar cells (PSCs).
• SnO2 colloids are thermodynamically unstable in aqueous solutions, leading to aggregation and precipitation, hindering device performance.

Purpose of the Study:

• To develop a stable synthesis strategy for SnO2 nanoparticle colloids.
• To improve the efficiency and operational stability of perovskite solar cells using stabilized SnO2 electron transport layers.

Main Methods:

• A phosphate-buffered synthesis strategy was employed to stabilize SnO2 colloids.
• The buffer maintained stable pH, regulating electrostatic repulsion to prevent nanoparticle aggregation.
• Controlled surface hydroxyl groups and oxygen vacancies in SnO2 films.

Main Results:

• Stabilized SnO2 colloids enabled efficient electron transport and reduced interfacial recombination.
• Perovskite solar cells achieved a power conversion efficiency (PCE) of 26.40% with high operational stability.
• A 5 cm × 5 cm perovskite solar module demonstrated a PCE of 23.11%.

Conclusions:

• The phosphate-buffered synthesis effectively stabilizes SnO2 colloids for high-performance PSCs.
• This strategy is scalable for manufacturing large-area, efficient perovskite solar modules.
• The method offers a viable route for advancing stable and efficient perovskite photovoltaics.