Constructing an Interfacial Gradient Heterostructure Enables Efficient CsPbI₃ Perovskite Solar Cells and Printed...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Cesium lead iodide perovskite solar cells (CsPbI₃ PSCs) suffer from poor performance due to interfacial defects and energy level misalignment.
• Nonradiative recombination at interfaces is a major limitation for achieving high-efficiency PSCs.

Purpose of the Study:

• To develop an effective interfacial engineering strategy for CsPbI₃ PSCs.
• To suppress nonradiative recombination and improve charge carrier dynamics.
• To enhance the overall efficiency and stability of CsPbI₃ PSCs.

Main Methods:

• Fabrication of CsPbI₃ PSCs using a low-temperature post-treatment with quaternary bromide salts.
• Creation of an interfacial gradient heterostructure.
• Analysis of ion diffusion, defect healing, and energy level alignment using advanced characterization techniques.

Main Results:

• Achieved a champion power conversion efficiency of 21.31% with a fill factor of 0.854 for CsPbI₃ PSCs.
• Demonstrated improved charge separation and collection due to optimized interfacial energy levels and reduced nonradiative recombination.
• Reported a record efficiency of 16.60% for 12 cm² printed CsPbI₃ minimodules and superior stability for unencapsulated devices.

Conclusions:

• The developed interfacial gradient heterostructure effectively heals defects and optimizes energy level alignment in CsPbI₃ PSCs.
• The post-treatment method offers a viable route for fabricating high-performance and stable CsPbI₃ perovskite solar cells.
• This approach paves the way for the commercial application of efficient and durable CsPbI₃ PSC technology.