Impurity PbCO₃ from Low-Purity Raw Material Improves MAPbBr₃ Single-Crystalline X-ray Detectors

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Perovskite single crystals show promise for X-ray detection and imaging.
• High-purity raw materials are traditionally needed for quality crystals, increasing costs.
• Understanding factors influencing crystal quality is crucial for cost-effective production.

Purpose of the Study:

• To investigate the effect of low-purity raw materials on MAPbBr3 single crystal quality.
• To identify the role of specific impurities in enhancing crystal properties.
• To develop a cost-effective method for producing high-performance perovskite X-ray detectors.

Main Methods:

• Growth of MAPbBr3 single crystals using varying purity lead bromide (PbBr2).
• Incorporation of lead carbonate (PbCO3) impurity into the raw materials.
• Characterization of crystal quality, defect concentration, and surface morphology.
• Performance evaluation of X-ray detectors fabricated from these crystals.

Main Results:

• Low-purity PbBr2 with PbCO3 impurity yielded higher quality MAPbBr3 single crystals.
• PbCO3 suppressed crystal defects, resulting in smoother surfaces and improved uniformity.
• The product of carrier mobility and lifetime increased to 1.3 × 10^-2 cm^2 V^-1.
• X-ray detector sensitivity doubled, and the detection limit decreased 300-fold to 20 nGyair/s.

Conclusions:

• Lead carbonate impurity in low-purity PbBr2 is beneficial for growing high-quality MAPbBr3 single crystals.
• This finding offers a new, cost-effective approach for high-yield perovskite single crystal production.
• The enhanced crystal quality translates to significantly improved X-ray detection performance.