Researchers at Florida State University (FSU) have developed new materials that could change the way X-ray detectors are made and used. The work, led by Professor Biwu Ma from the Department of Chemistry and Biochemistry, focuses on creating less expensive and more adaptable materials for X-ray detection.
In two recent studies, Ma’s group addressed challenges in X-ray imaging. In the first study, published in Small, the team created a material that generates electric signals when exposed to X-rays, allowing for direct detection. In the second study, published in Angewandte Chemie, they developed a related material to produce low-cost scintillators—substances that emit visible light when hit by X-rays or other high-energy radiation.
“We have traditionally relied on inorganic materials for X-ray detection, but they are often rigid, expensive to manufacture and energy-intensive to produce, and they have many limitations,” said Ma. “What we have been trying to develop is a new class of materials that can address the issues and challenges faced by existing materials.”
The research introduced hybrid materials called organic metal halide complexes (OMHCs) and organic metal halide hybrids (OMHHs). By adjusting these compounds at the molecular level, the team enabled different forms of X-ray detection. This approach aims to create lower-cost, scalable, and flexible detector technologies that overcome limitations found in conventional systems.
Current commercial direct X-ray detectors use inorganic semiconductors such as cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe), which contain toxic elements and require energy-intensive processing. In their first study, FSU researchers showed OMHCs can be used for direct detection. They made these from zinc, bromine, and carbon-based molecules. Using a melt-processing method similar to melting plastics into shapes, they formed glass-like OMHC films suitable for use as detectors.
These new detectors produced strong electrical responses even at low levels of exposure and retained 98% of their performance after four months under normal conditions. According to Ma: “This is actually the first time these OMHC materials have been used to fabricate direct X-ray detectors. They can be prepared in a low-cost way while delivering high performance. From a sustainability perspective, this new class of materials offer tremendous advantages over conventional materials.”
In their second study, the team improved OMHH-based scintillators so they respond quickly—within nanoseconds—and give off strong light output. Unlike previous versions that needed slow crystal growth processes or had lingering light emission from metal centers, these new amorphous OMHHs emit from their organic components with faster response times while still absorbing X-rays efficiently.
Fast-response scintillators are important for advanced radiation detection because they provide clearer images and better timing accuracy—important features for medical imaging or security screening.
The flexibility of these amorphous films also allowed researchers to create fabric-based scintillators that could be integrated into clothing for wearable radiation detectors—a shift away from traditional rigid devices.
FSU has started filing patents on these technologies with plans to test them outside the lab setting. Potential uses include medical imaging, security scanning, nuclear safety applications and more.
The research involved collaboration with Delft University of Technology (TU Delft), University of Antwerp, University at Buffalo and Qrona Technologies on projects ranging from photon-counting computed tomography to pixelated imagers.
“The materials are very unique and were developed here at FSU,” said Ma. “We believe our materials and devices have tremendous potential to outperform existing technologies and address key challenges in the field.”
Funding came from the National Science Foundation Division of Materials Research and Innovation and Technology Ecosystems. Lead authors included Oluwadara Joshua Olasupo—a recent Ph.D.—and Tarannuma Ferdous Manny—a fourth-year graduate student—with contributions from TU Delft and University at Buffalo researchers as well as high school students through FSU’s Young Scholars Program.
