A two-layer structured PbI2 thin film for efficient planar perovskite solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Perovskite solar cells (PSCs) offer promising photovoltaic performance.
• Efficient charge extraction and minimal recombination are critical for high-efficiency PSCs.
• Developing advanced interfacial layers is key to overcoming performance limitations in PSCs.

Purpose of the Study:

• To engineer a two-layer structured lead iodide (PbI2) thin film for planar perovskite solar cells.
• To investigate the impact of the structured PbI2 film on charge recombination and transport.
• To enhance the overall photoelectric conversion efficiency of perovskite solar cells.

Main Methods:

• Fabrication of a two-layer PbI2 thin film using spin-coating and vacuum thermal evaporation.
• Conversion of the PbI2 layers into compact and porous perovskite films.
• Characterization of planar perovskite solar cells incorporating the structured PbI2 layers.

Main Results:

• The bottom PbI2 layer formed a compact film, suppressing charge recombination.
• The top PbI2 layer formed a porous nano-sheet array, improving hole migration.
• Planar perovskite solar cells achieved a photoelectric conversion efficiency of 11.64%.

Conclusions:

• The two-layer structured PbI2 thin film effectively optimizes charge dynamics in PSCs.
• This approach leads to improved open-circuit voltage, photocurrent density, and fill factor.
• The developed structure presents a viable strategy for enhancing perovskite solar cell performance.