Flexible X-Ray Detectors Conform to Individual Specifications

A new study describes how x-ray detectors based on organic semiconductor technology could lead to tailor-made mammogram machines and more accurate security screenings at airports.

Under development at the University of Surrey (Guildford, United Kingdom) and the Siemens Healthineers Technology Center, the broadband X-ray detector concept is based on a thin film, hybrid semiconductor diode consisting of an organic bulk heterojunction (BHJ) with embedded bismuth oxide (Bi2O3) nanoparticles. The hybrid detectors demonstrate high sensitivities for both soft and hard X-rays generated from a medical linear accelerator, all achieved at low bias voltages and low power consumption.

According to the researchers, the new detectors can strongly compete with current technologies over the whole x-ray energy range spectrum. In addition, it is possible to create the organic semiconductor detectors so that they conform to the subject, something not possible with current rigid x-ray detectors. A new start-up company has been formed to further develop the technology and bring it to market, targeting the health, food monitoring, and pharmaceuticals sectors. The study was published on July 26, 2018, in Nature Communications.

“Our new technology has the potential to transform many industries that rely on x-ray detectors,” said lead author Hashini Thirimanne, MSc, a PhD student at the University of Surrey. “We believe that this innovation could help save lives, and keep our borders more secure, and make sure that the food we eat is as safe as it could possibly be.”

Current X-ray detector sensitivities are limited by the X-ray attenuation of the materials used, and consequently necessitate thick crystals, resulting in rigid structures, high operational voltages, and high cost. Increasing attention is thus being given to organic photodetectors for X-ray detection, which often involve the coupling of scintillator screens with organic photodiodes, insertion of high-atomic number nanoparticles, quantum dots, or scintillator particles into organic diodes, or the use of thin film organic semiconductors or crystals.

Related Links:
University of Surrey