X-ray imaging is one of the most widely used tools in modern medicine. It helps doctors see teeth, bones, lungs, and many other structures inside the body. But it also raises a long-standing challenge: clearer images usually require more X-rays, while radiation exposure should be kept as low as reasonably possible, especially for children, repeated examinations, and large-scale screening.
A research team has now reported a new way to address this challenge from inside the detector material itself. In a study published in National Science Review, the team developed a perovskite X-ray detector film that is more uniform from top to bottom. This vertical uniformity helps suppress the image noise that becomes especially serious when the X-ray dose is very low.
At low doses, the problem is not simply that there are fewer X-rays. The incoming X-ray photons arrive with natural statistical fluctuations, much like the grainy noise seen in a photo taken at night. In a thick detector film, X-rays may be absorbed at different depths. If the material is not uniform through its thickness, signals produced at different depths may be collected unevenly. This can amplify the original fluctuations and turn them into visible noise and spots in the final image.
To reduce this effect, the researchers designed a liquid-phase growth and annealing strategy, called LPGA. Instead of allowing strong temperature and composition differences to develop during film formation, this approach creates a more stable liquid-phase environment for growing and annealing thick perovskite films. The result is a detector film that is not only smooth at the surface, but also more consistent throughout its depth. This improved internal uniformity led to a clear imaging benefit. The LPGA detector showed much lower image noise than control devices. It also maintained stable X-ray response and produced high-quality images under ultralow-dose conditions.
In one dental imaging demonstration, the detector clearly revealed the crown and root regions of a tooth at a dose far below that used in a commercial dental X-ray comparison. The team also demonstrated imaging of objects such as a bat skeleton, walnut, and orange slice, showing that the detector can preserve fine structural details in different types of samples.
The study suggests that low-dose X-ray imaging does not have to rely only on better electronics or post-processing algorithms. The detector material itself can play a decisive role. By making the perovskite film more uniform through its thickness, the researchers reduced the internal source of image noise before it reached the readout circuit. The findings point to a promising materials-based strategy for safer and clearer X-ray imaging. In the future, detectors with lower noise at lower doses may support medical diagnosis, AI-assisted image analysis, and broader screening applications.
National Science Review
Experimental study