Passivation Mechanism Exploiting Surface Dipoles Affords High-Performance Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face challenges with stability and voltage limitations.
• Two-dimensional (2D) perovskites offer potential solutions, but the impact of other dimensionalities is less understood.

Purpose of the Study:

• To investigate the effect of quasi-three-dimensional (quasi-3D) azetidinium lead iodide (AzPbI3) as a secondary layer in PSCs.
• To determine if AzPbI3 can enhance photovoltaic parameters and address stability issues.

Main Methods:

• Fabrication of a perovskite solar cell device with a primary 3D perovskite film and a secondary quasi-3D AzPbI3 layer.
• Characterization of the photovoltaic performance and stability of the fabricated devices.

Main Results:

• The quasi-3D AzPbI3 layer significantly improved photovoltaic parameters compared to standard 3D perovskite films.
• A novel passivation mechanism was identified, attributed to surface dipoles introduced by AzPbI3.
• Achieved a power conversion efficiency (PCE) of 22.4% and an open-circuit voltage (Voc) of 1.18 V.
• Demonstrated a low voltage deficit of 0.37 V for a band gap of 1.55 eV.

Conclusions:

• Quasi-3D AzPbI3 is an effective material for enhancing the efficiency and stability of perovskite solar cells.
• The surface dipole passivation mechanism offers a new strategy for optimizing PSC performance.
• The achieved high open-circuit voltage highlights the potential of this approach for next-generation solar energy technologies.