PbI₂ -DMSO Assisted In Situ Growth of Perovskite Wafers for Sensitive Direct X-Ray Detection

Area of Science:

• Materials Science
• Solid-State Physics
• Detector Technology

Background:

• Polycrystalline perovskite wafers are suitable for X-ray detection due to scalable size and thickness.
• However, they suffer from high defect density, defective grain boundaries, and low crystallinity, limiting performance.

Purpose of the Study:

• To enhance the crystallinity and reduce defect density of MAPbI₃ perovskite wafers for improved direct X-ray detection.
• To investigate the use of PbI₂-DMSO powders as an additive to facilitate in situ crystal growth.

Main Methods:

• PbI₂-DMSO powders were prepared and introduced into MAPbI₃ wafers.
• The wafers underwent isostatic pressing, where released DMSO vapor facilitated in situ crystal growth.
• Characterization of the resulting MAPbI₃ wafer and fabrication of a direct X-ray detector.

Main Results:

• A dense and compact MAPbI₃ wafer with enhanced crystallinity and reduced defect density was produced.
• The wafer exhibited a high mobility-lifetime (µτ) product of 8.70 × 10⁻⁴ cm²/V.
• The fabricated MAPbI₃-based X-ray detector showed high sensitivity (1.58 × 10⁴ µC Gyair⁻¹ cm⁻²) and a low detection limit (410 nGyair s⁻¹).

Conclusions:

• The in situ growth method using PbI₂-DMSO additives effectively improves perovskite wafer quality for X-ray detection.
• This approach offers a promising pathway for developing high-performance perovskite-based X-ray detectors.