UNL Researchers Developing New Material to Lessen X-Ray Exposure

[Mavric]

In a March 21 study published by the journal Nature Photonics, the researchers reveal a crystalline material that is four times more sensitive to X-rays than leading commercial detectors. Known as methylammonium lead tribromide, the material can detect an X-ray dose about 11 times lower than that required for many medical applications.

X-rays have become a staple of medical diagnoses since their discovery in 1895, helping detect fractures in bones and reveal tumors in tissue. The rise of global terrorism has also increased their use for security purposes, particularly in the transportation industry.

Yet X-rays also represent a form of radiation that can damage tissue and raise the lifetime risk of developing cancer, which increases with the dose and number of exposures. That risk rises further among those exposed to X-rays at a young age, according to the National Institute of Biomedical Imaging and Bioengineering.

UNL engineer Jinsong Huang and colleagues recently began exploring methylammonium lead tribromide as a candidate for limiting this exposure. The material belongs to a family of compounds known as perovskites that Huang has studied since 2013 in his efforts to improve the performance of solar cells and photodetectors.

"If you look at the history of X-ray detectors, the materials used for them are usually also good for photovoltaic devices," said Huang, a Susan J. Rosowski associate professor of mechanical and materials engineering. "This material is almost perfect for X-ray applications."

The material's X-ray sensitivity stems in part from its large atomic weight, or the number of protons residing in each of its atoms. These heavier atoms are able to absorb more of the high-energy photon particles that constitute X-rays, making their parent material sensitive to smaller doses of the radiation.

Certain detectors take advantage of the fact that X-ray photons possess enough energy to knock loose atom-orbiting electrons, which have a negative charge and leave positively charged "holes" in their wake. When electrodes are placed at either end of a semiconducting material such as methylammonium lead tribromide, the holes and electrons migrate in opposite directions to produce pulses of electric current that are ultimately translated into digital images.

 

UNL.edu

[Ratt Mhule]

As an xray technologist, i approve of anything that lowers the amount of radiation a person gets exposed to. Good job UNL. It also helps when doctors actually know what views to order and which ones are unnecessary and then you try and tell them you dont need that view, they get mad and yell at you for questioning a doctor.