FSU Chemists Revolutionize X-ray Detection with New Thin Films

Research conducted by a team at Florida State University (FSU) has advanced X-ray detection technology through the development of innovative thin films. Led by Professor Biwu Ma from the Department of Chemistry and Biochemistry, the project focuses on a new form of X-ray material that addresses the need for larger and more adaptable detection systems. The findings were published in the journal Angewandte Chemie.

Traditionally, X-ray technology evokes images of medical diagnostics, such as detecting bone fractures. However, its applications extend into various fields, including airport security, manufacturing, and scientific research. The novel thin-film detectors created by Ma’s team offer significant improvements, moving away from complex crystal structures to a more versatile approach.

Zero-dimensional organic metal halide hybrids, termed 0D OMHHs, are at the heart of this innovation. These materials combine organic components with inorganic metal halides, allowing researchers to exploit the advantageous properties of both. The goal is to provide high-performance, low-cost materials that can be used directly for X-ray detection.

Previously, Ma’s team had demonstrated the potential of 0D OMHH single crystals for X-ray detectors. However, the scalability of these crystals was hindered by a laborious growth process. The new amorphous OMHH films, which are mere millimeters thick, can be easily fabricated into larger and custom-shaped detectors, broadening their application in fields like astronomy, materials science, and medical imaging.

“If a doctor wants to take an X-ray image of someone’s chest, it’s crucial to have a detector large enough to cover the entire area for an accurate image,” Ma explained. “With our new amorphous film material, we have the potential to create larger and more versatile X-ray detectors.”

Understanding the Technology

The 0D OMHHs consist of positively charged organic cations bonded to negatively charged metal halide units. This structure allows for highly adjustable properties, making the material suitable for various applications, including light-emitting diodes (LEDs) and anti-counterfeiting technologies. The team’s recent work involved creating amorphous films by combining non-crystalline organic molecules with metal halides, which enables efficient conversion of X-rays into electrical signals for image generation.

These amorphous films boast high sensitivity, low detection limits, and excellent stability, reinforcing their potential for widespread adoption in the construction of detectors. The resulting films exhibit uniformity and smoothness, with their size, thickness, and area easily adjustable based on precursor solution concentration and mold dimensions.

Broader Applications and Future Prospects

X-rays play a critical role in numerous applications, from medical diagnostics to non-destructive industrial testing. They are essential for inspecting welds, detecting cracks in materials, and ensuring the integrity of structures. Additionally, X-ray detectors contribute significantly to security measures, such as scanning luggage in airports and identifying hazardous materials in parcels.

The capacity of large-area X-ray detectors enhances imaging quality, leading to higher resolution images and faster scanning throughput. This is particularly beneficial in industries like cargo inspection, where efficiency is paramount. As Wei Yang, chair of the Department of Chemistry and Biochemistry, stated, “The significance of this work lies in the enabling of possible industrial processing for large-area detection, which is crucial for the material’s applicability.”

In April 2023, a provisional patent application titled “Direct X-ray Detectors Based on Solution-Processed Amorphous Zero-Dimensional Organic Metal Halide Hybrid Films” was filed with the U.S. Patent and Trademark Office. Ma is also in discussions to launch a company with an industry partner to commercialize these technologies, marking a significant step toward practical application.

Reflecting on the journey of developing these materials, Ma noted, “Since first publishing on these materials almost a decade ago, I have worked with my colleagues to push the boundaries of what they can achieve. We see 0D OMHHs as versatile and powerful, with the potential to offer a better alternative in many fields.”

The research involved contributions from several individuals, including doctoral student Oluwadara Olasupo, who served as the publication’s lead author, and various members of Ma’s research group. Support for this project was provided by the National Science Foundation and the FSU Office of Research. Additionally, high school student Ethan Kim participated through FSU’s Young Scholars Program.

To explore more about Ma’s work and related research at the Department of Chemistry and Biochemistry, visit chem.fsu.edu.