Researchers from Exciton Science have shown a way to multi-energy X-Ray detection with considerably improved flexibility and sensitivity, suggesting a potential paradigm shift in imaging applications.
Image Credit: Exciton Science
The technology was created by a team at Monash University and is built on printable, solution-processed perovskite thin films, a material more frequently found in next-generation solar energy devices.
The prestigious journal Advanced Materials published the study’s findings.
These perovskite-based detectors can provide rapid response times and offer high sensitivities to enable real-time detection and imaging for complex purposes, including disease diagnoses, detection of explosives, and identifying food contamination.
Dr. Babar Shabbir, Study First Author and Senior Research Fellow, Exciton Science
Most X-Ray detectors work in either hard or soft energy levels. While soft X-Rays are necessary for properly imaging living matter such as tissue and cells, hard X-Rays are used to pierce thick materials like rock or bone.
In the hard X-Ray region between 10 and 100-kilo electron volts (KeV), single-energy measurement is typically carried out. Energy levels below 1 KeV might be necessary for detection in the soft window.
An X-Ray detector must occasionally be capable of operating at both energy levels. For example, when looking for tumors within the breast tissue.
Existing multi-energy X-Ray detectors are made of silicon and selenium, and while they can function in both energy regions, their energy sensitivity and spatial precision are constrained.
The development of metal halide perovskites represents a hopeful and possibly much more efficient and adaptable substitute.
Perovskite materials, so named owing to their crystal structure, can successfully control the intensity of an X-Ray beam as it travels through matter, a process known as X-Ray attenuation. They are also cheap to produce.
It is crucial to note that the X-Ray attenuation process causes the creation of charges during the fabrication of the perovskite in a diode device, which can be successfully gathered to provide a signature of the X-Ray energy and strength.
It has been shown in this new study that perovskite-based multi-energy X-Ray detectors can function over a wide energy range, 0.1 KeV to the 10 s of KeV, which is considerably wider than the current generation of conventional multi-energy X-Ray detectors.
Previous perovskite-based device demonstrations were restricted to hard X-Ray detection on a small size spanning from millimeters to centimeters.
Perovskites have not only been used for soft X-Ray detection for the first time, but the new technique is also appropriate for scaling up to the vast regions required for commercial use.
Furthermore, since the perovskite detectors will be produced as thin films, they could be coupled with flexible substrates to create a variety of new device forms and sizes.
This work showcases that there is a natural extension of perovskites into printed X-ray detectors. They should be cheaper to make, and could also involve modified film form factors, where you need inherent flexibility. It opens up the field to a whole new set of questions about how to use these types of devices.
Jacek Jasieniak, Study Senior Author and Chief Investigator, Exciton Science
The University of Illinois, the University of Cambridge, the CSIRO of Australia, and Nanyang Technological University in Singapore all contributed to this study.
Journal Reference:
Shabbir, B., et al. (2023) Printable Perovskite Diodes for Broad-Spectrum Multienergy X-Ray Detection. Advanced Materials. doi:10.1002/adma.202210068.