Large Scale Production of Photonic Crystals on Scintillators

Heavy inorganic scintillator based detectors are used in various applications. You can find them in high energy physics as well as in nuclear medical imaging systems but also in homeland security radiation monitoring devices. In all these different detectors, light is produced in the scintillator and has to be transported towards a photodetector. The standard optical coupling of such a detector suffers from an inefficient light extraction towards the photodetector due to the high index of refraction of the scintillator and the accompanying total internal reflections. With the means of photonic nanostructuring of the different surfaces of the scintillator, the light transport can be optimized, which has a direct impact on the timing and light yield performance of the detector. Previous work from our group has already shown that photonic crystals (PhCs) can be used as diffraction gratings to improve the light coupling between a photodetector and a scintillator. Moreover, nanoscale surface structuring techniques could also be extended to the sidewalls, the wrapping, or the detector itself, which would open up a number of new possibilities for optimization of the light transport of scintillation based detectors. To show that PhCs can also be produced on a large industrial scale, we started to investigate different methods for cheap and large area PhC structuring. In this work, the current results on our efforts on PhC scintillator production will be described. The different projects include nanoimprint technologies, interference lithography and colloidal lithography. To conclude, we will summarize the different efforts of our group and collaborators and show up-to-date results of PhC improved scintillators.