A hole-conductor-free, fully printable mesoscopic perovskite solar cell with high stability

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) are promising for next-generation photovoltaics.
• Current PSC fabrication often relies on hole-transporting layers, adding complexity and cost.
• Defect control and efficient charge separation are critical for PSC performance and stability.

Purpose of the Study:

• To develop a hole-transport-layer-free perovskite solar cell.
• To investigate the use of a mixed-cation perovskite with a double-layer scaffold for improved performance.
• To enhance perovskite crystal quality and charge separation efficiency.

Main Methods:

• Fabrication of a perovskite solar cell using a mesoporous TiO2 and ZrO2 scaffold.
• Preparation of a mixed-cation perovskite ((5-AVA)x(MA)1-xPbI3) via a drop-casting method incorporating 5-ammoniumvaleric acid (5-AVA) iodide.
• Characterization of perovskite crystal structure, defect concentration, pore filling, and charge separation dynamics.

Main Results:

• The 5-AVA templating resulted in mixed-cation perovskite crystals with reduced defect concentration and improved pore filling.
• Enhanced contact between the perovskite and the TiO2 scaffold led to longer exciton lifetimes and higher quantum yields for charge separation.
• The fabricated solar cell achieved a certified power conversion efficiency of 12.8%.
• The device demonstrated excellent stability, maintaining performance for over 1000 hours in ambient air under sunlight.

Conclusions:

• A hole-transport-layer-free perovskite solar cell architecture utilizing a TiO2/ZrO2 scaffold is feasible and effective.
• Incorporating 5-ammoniumvaleric acid (5-AVA) into the perovskite formulation significantly improves crystal quality and photovoltaic performance.
• The developed perovskite solar cell exhibits high efficiency and remarkable operational stability, paving the way for practical applications.