Elucidating Structure Formation in Highly Oriented Triple Cation Perovskite Films.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• Metal halide perovskites are promising semiconductors for optoelectronics.
• Their properties depend on composition, crystal structure, and microstructure.
• Controlling crystalline orientation in perovskite films is crucial but underexplored.

Purpose of the Study:

• Investigate perovskite film formation and crystalline orientation.
• Understand the role of antisolvents in templating perovskite crystallization.
• Correlate film orientation with device performance and stability.

Main Methods:

• Fabrication of highly oriented triple cation perovskite films.
• Use of various alcohols as antisolvents.
• In situ grazing-incidence wide-angle X-ray scattering (GISAXS) for real-time analysis.

Main Results:

• Discovery of a short-lived, highly oriented crystalline intermediate (FAI-PbI2-xDMSO).
• This intermediate acts as a template for the final perovskite layer.
• Antisolvent properties (alcohol type) influence the degree of perovskite orientation.
• DMSO-containing intermediate formation is triggered by selective DMF removal.

Conclusions:

• Antisolvent engineering is key to controlling perovskite crystalline orientation.
• Highly oriented perovskite films lead to improved photovoltaic device performance.
• Enhanced stability is observed in devices fabricated from oriented films.