Unlocking the intermediate-phase evolution in perovskite crystallization with an operando infrared FEWS sensor

Area of Science:

• Materials Science
• Spectroscopy
• Crystallization Science

Background:

• Intermediate phases are crucial in perovskite crystallization but difficult to monitor.
• Effective in situ monitoring is key to controlling perovskite crystal quality.

Purpose of the Study:

• To develop a real-time, non-destructive method for monitoring intermediate-phase evolution during perovskite crystallization.
• To gain insights into the complexation and decomplexation dynamics of perovskite precursors.

Main Methods:

• Utilized infrared fiber evanescent wave spectroscopy (FEWS) with GeAsSeTe chalcogenide optical fibers.
• Operando captured vibrational and rotational dynamics of molecular functional groups.

Main Results:

• Successfully monitored the intermediate-phase evolution in BM2PbBr4 perovskite crystallization.
• Observed spectral shifts indicating Pb2+ complexation with DMF carbonyl groups and subsequent decomplexation.
• Identified new vibrational bands suggesting changes in DMF-BMBr hydrogen bonds.

Conclusions:

• FEWS provides novel insights into perovskite crystallization processes.
• This technique facilitates the control of crystal quality for high-performance perovskite materials.
• Advances the development of perovskite-based photovoltaic and optoelectronic devices.