Organic scintillator materials shine brightly in X-ray research

When a scintillator is struck by high-energy ionising radiation such as X-rays, it absorbs the energy and reemits some of it as low energy visible light. Scintillators are widely used for X-ray imaging screens in applications including airport security scanners and medical radiography, and many are made from ceramic or perovskite materials, which are often fabricated under harsh conditions and suffer from poor stability over time when exposed to light and air.

“Organic-based scintillators have inherent advantages, such as low toxicity, high mechanical flexibility, low cost and straightforward large-scale production,” said Jian-Xin Wang at KAUST (King Abdullah University of Science and Technology), who worked on the project under the supervision of Omar Mohammed and colleagues. “However, balancing the X-ray absorption capability, exciton utilisation efficiency and photoluminescence quantum yield of organic scintillators has proven challenging.”

According to KAUST, organic scintillator materials have so far been hampered by the small range of X-ray frequencies that they can naturally absorb. Wang and colleagues realised that X-ray absorption should increase as the atomic number of the incorporated elements increases and the team hypothesised that the addition of heavy atoms to the scintillator material could resolve this issue as x-ray photons interact efficiently with heavy atoms due to their photoelectric effect.