Structural stability and optoelectronic properties of tetragonal MAPbI₃ under strain

Area of Science:

• Materials Science
• Solid State Physics
• Photovoltaics

Background:

• Organic-inorganic hybrid perovskites exhibit promising optoelectronic properties for device applications.
• Perovskite films in solar cells experience residual stress, impacting stability and performance.
• The precise effects of strain on perovskite structural integrity and photovoltaic efficiency remain unclear.

Purpose of the Study:

• To investigate the influence of external strain on the structural stability and optoelectronic characteristics of tetragonal methylammonium lead iodide (MAPbI3).
• To elucidate the relationship between strain, ion migration barriers, and material properties.
• To provide guidance for optimizing perovskite solar cell performance and commercialization.

Main Methods:

• First-principles calculations were employed to simulate the behavior of MAPbI3 under various strain conditions.
• Analysis focused on ion migration barriers, light absorption spectra, and electronic band structure.
• Investigated the impact of compressive and tensile strains, including triaxial and biaxial configurations.

Main Results:

• Compressive strain increases the migration barrier of iodide ions, enhancing structural stability.
• Tensile strain decreases the iodide ion migration barrier.
• Compressive strain improves light absorption and electronic properties of MAPbI3.
• Band gap variations under different strain types are consistent, driven by Pb-I bond changes.

Conclusions:

• Compressive strain is beneficial for the structural stability of methylammonium lead iodide (MAPbI3) perovskite films.
• Strain engineering can significantly enhance the optoelectronic properties and photovoltaic performance of perovskite solar cells.
• These findings support the commercial application of MAPbI3-based solar technologies.