Controlling the Phase Transition in CsPbI₃ Nanowires.

Area of Science:

• Materials Science
• Solid-State Physics
• Nanotechnology

Background:

• Cesium lead iodide (CsPbI₃) is a semiconductor with optoelectronic potential.
• CsPbI₃ exhibits a metastable perovskite phase prone to transitioning into an unfavorable nonperovskite phase under ambient conditions.
• This phase transition degrades optoelectronic properties, limiting device applications.

Purpose of the Study:

• Investigate the kinetics of CsPbI₃ phase transitions.
• Understand the influence of environmental factors on phase stability.
• Develop strategies to control and stabilize the CsPbI₃ perovskite phase.

Main Methods:

• Utilized ultralong CsPbI₃ nanowires as a model system.
• Examined the effects of environmental stressors, specifically moisture and temperature, on phase transition dynamics.
• Demonstrated control over phase propagation on individual nanowires.

Main Results:

• Identified moisture and temperature as key environmental factors controlling CsPbI₃ phase transition kinetics.
• Showcased the ability to modulate phase transition dynamics by adjusting moisture levels and temperature.
• Provided a model platform for studying phase transition mechanisms in CsPbI₃.

Conclusions:

• Environmental stressors significantly influence CsPbI₃ phase transition dynamics.
• Controlling moisture and temperature enables stabilization of the CsPbI₃ perovskite phase.
• Findings offer guiding principles for designing stable CsPbI₃-based optoelectronic devices and photovoltaics.