The development and characterisation of large area inorganic-organic hybrid X-ray imagers

"SilverRay Ltd. is a start-up company whose primary goal is to exploit the technology developed in a large area, high sensitivity broad-band X-ray detectors. This proprietary technology has demonstrated its sensitivity to be 2-3 orders of magnitude higher than the conventional organic detectors; while operating at low voltage and offer excellent conformability to non-planar surfaces. One of its key selling points is the potential for low cost manufacurability of the technology over large areas.

The detector active material consists of an 'X-ray sensitive ink' containing an interpenetrating network of organic material and inorganic nanoparticles. The 'X-ray sensitive ink' can be used to coat films over any substrate, especially without constraints for flexible detectors. Thus far, small area detectors (area < 1 cm2) have been developed with the scale-up currently being carried out by SilverRay Ltd. Challenges lie within the production of uniform thick film coatings, where the company seeks for the application of uniform nanoparticle distributions through-out the film depth and spatially across pixel-to-pixel. A well-uniformed distribution of inorganic nanoparticles is crucial to the imager, as the high atomic number nanoparticles are the key component which makes the ink sensitive to X-rays and as a result generate charge carriers. Therefore, it is expected to have a uniform distribution of nanoparticles on each pixel of the backplane, so that the charge generation from each pixel due to X-rays is uniform and identical to each other.

In this project, we will focus on the fabrication of large area thick film coating and these films will be characterised by the A4I partners; NPL and LGC. They will be working on how to optimise their instrumentation further to analyse the uniformity of nanoparticles with higher precision towards its nanoscale morphology, and present a solution that can be implemented in an in-situ printing manufacturing environment. The outcome of this project will facilitate the company to have a better understanding on routes to optimise the active layer of the detector which would lead to higher performances and faster responses."