Getting an X-ray remains a little risky, as radiation exposure has been linked to an increased risk of cancer; however, researchers have discovered a new way to generate precise X-ray images with a lower amount of exposure.
The new class of X-ray detectors is based on layered perovskites, semiconducting materials also used in applications such as solar cells and light-emitting diodes. The detector with the new material is 100 times more sensitive than conventional, silicon-based X-ray detectors. This new material for detecting X-rays could find its way into everyday environments such as the doctor’s office and airport security.
The perovskite materials work because they are deposited as a sprayed-on thin film, a production method that helps to reduce cost compared to having to grow a large silicon single crystal.
The new perovskite detectors can also detect X-rays over a broad energy range, especially at higher energies. This is because the perovskite contains heavy elements, such as lead and iodine, that tend to absorb these X-rays more readily than silicon. The potential even exists for the perovskite technology to be used as a gamma-ray detector, provided the films are made a bit thicker and a small external voltage is applied. The perovskite material can be produced with low-cost process fabrication techniques.
The material and thin film were subjected to grazing incidence wide-angle X-ray scattering, which gives information about the crystallinity of the thin film. The technique shows how the crystal is oriented in the thin film, which relates to the performance of the detector.
The researchers also investigated how the charge transport properties of the film related to the crystal structure and temperature. Using a special stage that allowed the researchers to change the temperature of the sample and make electrical contacts during the measurement, they were able to understand the current generation and transport processes induced in the sample by the X-ray exposure.