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

“SilverRay有限公司是一家初创公司，其主要目标是开发大面积高灵敏度宽带x射线探测器的技术。该专利技术已证明其灵敏度比传统的有机探测器高2-3个数量级；在低电压下工作时，对非平面表面具有良好的适应性。其主要卖点之一是该技术在大范围内低成本制造的潜力。探测器活性材料由“x射线敏感墨水”组成，其中包含有机材料和无机纳米颗粒的互穿网络。这种“x射线敏感油墨”可用于在任何衬底上涂覆薄膜，特别是对柔性探测器没有限制。到目前为止，小面积探测器（面积< 1 cm2）已经开发出来，目前由SilverRay Ltd.进行放大。挑战在于均匀厚膜涂层的生产，该公司寻求在整个膜深度和像素到像素的空间上均匀分布纳米颗粒。无机纳米粒子的均匀分布对成像仪至关重要，因为高原子序数的纳米粒子是使油墨对x射线敏感并产生载流子的关键成分。因此，期望在背板的每个像素上有均匀分布的纳米颗粒，从而使每个像素由于x射线产生的电荷是均匀的，并且彼此相同。在这个项目中，我们将专注于制造大面积厚膜涂层，这些薄膜将由A4I合作伙伴进行表征；NPL和LGC。他们将研究如何进一步优化他们的仪器，以更高的精度分析纳米颗粒的均匀性，并提出一个可以在原位印刷制造环境中实施的解决方案。该项目的成果将有助于公司更好地了解路线，以优化探测器的有源层，从而实现更高的性能和更快的响应。”

"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."