The most common approach for using nanophotonics to improve the scintillated signal is to coat the thick bulk scintillator by a thin film (usually a 2D photonic crystal) that reduce the total internal reflected light and thus improve the amount of signal that is transmitted towards the photodetector. Thus, the coating improve the quantum yield of the scintillator, that is, the amount of visible photons that get extracted from the scintillator as a result of a single quanta of high-energy excitation. This approach can be beneficial for all scintillation applications (for example, medical imaging devices as PET-CT, airport security machines, and free-electron cameras). The best performance of this approach recently showed a 10-fold enhancement in the quantum yield in a micro-CT experiment.