Mapping and Characterization of Local Structures of CsPbBr₃.

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Inorganic perovskite CsPbBr₃ offers superior stability and optoelectronic properties compared to organic counterparts.
• High-energy radiation detection and optoelectronic applications demand a deep understanding of CsPbBr₃'s phase transitions.

Purpose of the Study:

• To investigate the temperature-dependent phase transitions of inorganic perovskite CsPbBr₃ at the atomic level.
• To correlate experimental observations with molecular dynamics simulations for a comprehensive analysis.

Main Methods:

• Experimental characterizations, including X-ray diffraction (XRD).
• Molecular dynamics simulations to model atomic behavior and electronic structure.
• Analysis of atomic density distributions and [PbBr₆] octahedra dynamics.

Main Results:

• Observed distinct phase transitions from monoclinic to cubic structures with increasing temperature.
• Simulations revealed temperature-driven changes in the electronic structure and dynamic behavior of Cs, Pb, and Br atoms.
• Identified dynamic tilting of [PbBr₆] octahedra above 410 K in the cubic phase.

Conclusions:

• The study elucidates the thermal stability and structural dynamics of CsPbBr₃.
• Provides fundamental insights into the phase behavior of inorganic perovskites.
• Offers crucial data for designing advanced optoelectronic and radiation detection devices.