CsPbBr₃ Nanocrystal Induced Bilateral Interface Modification for Efficient Planar Perovskite Solar Cells.

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Organic-inorganic halide perovskite solar cells (PSCs) show promise but suffer from defects limiting performance and stability.
• Wet-chemical synthesis methods commonly used for PSCs introduce bulk and interface defects, causing charge carrier recombination.

Purpose of the Study:

• To develop a bilateral interface modification strategy for perovskite layers in PSCs.
• To improve the photovoltaic performance and stability of PSCs by suppressing defects and enhancing charge transport.

Main Methods:

• Doping perovskite layers with room-temperature synthesized CsPbBr3 nanocrystals (CN).
• Utilizing ultrafast transient absorption spectroscopy to investigate defect suppression and electron transport.
• Employing in situ Kelvin probe force microscopy and contact potential difference measurements to analyze built-in electric field enhancement.

Main Results:

• CN doping effectively suppresses defects at the SnO2/perovskite interface, enhancing interfacial electron transport.
• CN incorporation in the upper perovskite layer strengthens the built-in electric field, promoting oriented carrier migration.
• Bilaterally modified CH3NH3PbI3-based planar PSCs achieved a power conversion efficiency exceeding 20% with improved stability.

Conclusions:

• Bilateral interface modification using CsPbBr3 nanocrystals is a viable strategy to enhance PSC performance.
• CN doping addresses key limitations in PSCs, including interface defects and charge transport.
• The developed method offers a pathway to highly efficient and stable perovskite solar cells.