Dual-Site Coordination Regulated Crystallization for High-Performance MAPbBr₃ X-ray Detection

Area of Science:

• Materials Science
• Crystallography
• Detector Physics

Background:

• Organic-inorganic hybrid perovskites are promising for sensitive X-ray detectors.
• Precursor solution instability causes defects, limiting device performance.

Purpose of the Study:

• To develop a strategy for high-quality perovskite single crystal growth.
• To improve the thermodynamic stability of perovskite precursor solutions.
• To enhance the performance of perovskite-based X-ray detectors.

Main Methods:

• Polyvinylpyrrolidone (PVP) as a polymeric inhibitor.
• Coordination mechanism analysis using IGMH and DFT calculations.
• Experimental characterization of single crystals and detector performance.

Main Results:

• PVP effectively suppresses disordered nucleation and maintains precursor stability.
• PVP forms a dual-site coordination complex with Pb2+.
• Perovskite single crystals exhibit low defect density (6.56 × 10^8 cm^-3) and high carrier mobility-lifetime product (1.11 × 10^-3 cm^2·V^-1).
• X-ray detectors show high sensitivity (1.73 × 10^4 μC·Gyair^-1·cm^-2) and low detection limit (43.55 nGyair·s^-1).

Conclusions:

• Coordination engineering with PVP is a viable strategy for high-quality perovskite crystallization.
• This approach enables the development of advanced, high-performance radiation detectors.
• The study offers a new pathway for modulating crystallization kinetics in perovskite materials.