Background: Since the discovery of X-rays by Röntgen in 1895, X-rays have been widely
applied in multiple disciplines and industries. Since the X-rays are well beyond human visibility,
materials are used for the high-energy X-ray detections. This review focuses on the X-ray detection
Methods: X-rays can be detected by (1) X-ray films, which is a traditional method for imaging; (2)
phosphor- or scintillator-based detectors, which are used as an indirect detection method to convert
the X-rays into visible lights; (3) semiconductor-based detectors, which are used as a direct detection
method for X-ray imaging and X-ray exposure measurements; and (4) gas detectors, which are used
for X-ray exposure measurements.
Results: Materials for X-ray detection were summarized, including phosphors, scintillators, and semiconductors.
Their characteristic properties were compared. Nano size effects on the X-ray detection
were discussed. X-rays can be detected using random nanomaterials (nanoparticles, nanofibers and
nanowires, nanocomposites). The scintillator and phosphor nanoparticles were found to exhibit enhanced
luminescence and shortened decay time, while luminescence suppression was also observed.
Assembly of a core/shell structure was suggested as a strategy to increase such luminescence intensity.
Nanofibers and nanowires have been prepared for improved spatial resolution. Since it is expensive and
also technically challenging to grow high-quality single crystal scintillators, alternative ways have been
developed to fabricate nanocomposites with scintillator or phosphor nanoparticles that demonstrated
high performance. For X-ray imaging, it is preferable to vertically align scintillator material to reduce
light cross scattering and to achieve higher spatial resolution; ideally by confining the scintillator inside
of walls with light guides. Finally, scintillators have been made in nanochannels for improved spatial
resolution and light output.
Conclusion: The application of nanomaterials for X-ray detection is limited when compared to other
applications using nanomaterials. The research on X-ray detection using nanomaterials is an open
field for conducting studies of excitation mechanisms, exploration of new scintillator materials, and
applications of active compounds.