Supple Formamidinium-Based Low-Dimension Perovskite Derivative for Sensitive and Ultrastable X-ray Detection

Area of Science:

• Materials Science
• Optoelectronics
• Detector Physics

Background:

• Halide perovskites exhibit excellent optoelectronic properties, making them suitable for direct X-ray detection.
• Perovskite wafers are scalable and easy to prepare, positioning them as promising candidates for X-ray detection and imaging.
• Polycrystalline perovskite detectors face challenges with device instability and current drift due to ionic migration.

Purpose of the Study:

• To investigate the potential of one-dimensional (1D) δ-phase formamidinium lead iodide (δ-FAPbI3) as an X-ray detection material.
• To assess the stability and performance of δ-FAPbI3 for X-ray imaging applications.
• To demonstrate the feasibility of δ-FAPbI3 wafer detectors in a practical imaging system.

Main Methods:

• Characterization of the optoelectronic properties of δ-FAPbI3, including its band gap (2.43 eV).
• Evaluation of ionic migration, Young's modulus, and long-term stability under atmospheric conditions (RH ≈70 ± 5%).
• Fabrication of a large-size δ-FAPbI3 wafer detector integrated with a thin-film transistor (TFT) backplane.

Main Results:

• δ-FAPbI3 demonstrates a suitable band gap for X-ray detection and imaging.
• The material exhibits low ionic migration, low Young's modulus, and excellent long-term stability.
• Exceptional atmospheric stability over six months and extremely low dark current drift (3.43 × 10⁻⁴ pA cm⁻¹ s⁻¹ V⁻¹) were observed.
• Successful direct 2D multipixel radiographic imaging was achieved using the fabricated δ-FAPbI3 wafer detector.

Conclusions:

• One-dimensional δ-FAPbI3 is a highly promising material for sensitive and ultrastable X-ray detection.
• Its inherent stability and low ionic migration overcome key challenges in perovskite detector technology.
• The successful demonstration of radiographic imaging validates δ-FAPbI3 wafer detectors for advanced imaging applications.