Multiple Interactions in Polar Lead-Free Perovskites toward Highly Stable X-Ray Detection

Area of Science:

• Materials Science
• Semiconductor Physics
• Radiation Detection

Background:

• Lead-free halide perovskites offer eco-friendly, high-performance X-ray detection.
• Ion migration under high electric fields limits the stability of current perovskite X-ray detectors.

Purpose of the Study:

• To enhance the stability of lead-free perovskite X-ray detectors.
• To investigate the role of multiple halogen interactions in improving ion migration resistance.
• To explore the potential for self-powered detection using chiral-polar perovskites.

Main Methods:

• Design of 0D polar bismuth halide perovskites (R/S-BPEA)4Bi2I10 with Br-substituted chiral organic cations.
• Incorporation of molecular electrostatic forces and Br···I halogen interactions.
• Characterization of ion migration activation energy, dark current drift, operational stability, and air stability.
• Evaluation of self-powered detection capabilities and detection limits.

Main Results:

• Introduction of multiple halogen interactions significantly improves ion migration activation energy.
• Achieved a low dark current drift of 3.25 × 10^-8 nA cm^-1 s^-1 V^-1 at 2500 V cm^-1.
• Demonstrated excellent operational stability under prolonged X-ray irradiation and 90-day air exposure.
• Exhibited potential for self-powered detection with a low detection limit of 183 nGy s^-1 at zero bias.

Conclusions:

• Multiple halogen interactions in lead-free perovskites effectively suppress ion migration, leading to highly stable X-ray detectors.
• The developed perovskite materials show promise for robust, long-term radiation detection applications.
• Chiral-polar perovskites offer a pathway towards developing efficient, self-powered, and environmentally friendly radiation detection devices.