Solvent-Assisted Preparation of High-Performance Mesoporous CH₃NH₃Pbl₃ Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Organometal trihalide perovskite solar cells have rapidly advanced, with power conversion efficiencies (PCE) exceeding 15% within three years.
• Mesostructured perovskite solar cells utilizing CH₃NH₃PbI₃ as the light-harvesting material show significant improvements in performance and reproducibility.

Purpose of the Study:

• To develop a mesoscopic TiO₂/CH₃NH₃PbI₃ heterojunction solar cell with a uniform perovskite thin film.
• To evaluate the performance, reproducibility, and potential for low-cost fabrication of these perovskite solar cells.

Main Methods:

• Fabrication of a uniform perovskite thin film using a solvent-assisted solution processing method.
• Construction of a mesoscopic TiO₂/CH₃NH₃PbI₃ heterojunction solar cell architecture.
• Characterization of device performance, including photocurrent density, open-circuit voltage, fill factor, and power conversion efficiency (PCE).

Main Results:

• The best performing solar cell achieved a photocurrent density of 20.11 mA cm⁻², an open-circuit voltage of 1.02 V, and a fill factor of 0.70.
• The power conversion efficiency (PCE) reached 14.41%, with a small anomalous hysteresis observed in the J-V curves (PCE forward scan was 84% of reverse scan).
• Statistical analysis confirmed reproducible and high PCEs for the perovskite solar cells prepared using the reported method.

Conclusions:

• The solvent-assisted solution processing method enables the fabrication of uniform perovskite thin films for efficient solar cells.
• The mesoscopic TiO₂/CH₃NH₃PbI₃ heterojunction solar cells demonstrate promising performance and reproducibility.
• This approach offers a viable pathway for the development of low-cost, high-efficiency perovskite solar cells.