Quantum-Dot-Based Scintillators

There is a large demand today for ultrafast timing detectors, and in particular for scintillator-based detectors. Particle physics experiments running at future accelerator facilities count on such fast-timing detectors to cope with the high event pileup due to the increase in luminosity and to enable particle identification capabilities. TOF techniques and event tagging with a minimum precision of 30ps can achieve pileup suppression by more than a factor of 10. The improvement of time resolution can be achieved with scintillators with a high photon density. Standard bulk scintillating materials are able to convert energy from high energetic impacts into optical photons at a rate of at most one photon per MeV per picosecond with approximately 50% efficiency which are nonetheless delayed by a risetime of the order of 100ps. This restricts the amount of information available within the first few picoseconds after the particle or gamma has interacted and is governed by the emission centre excited states decaying to their ground states with typical relaxation times of at least tens of ns. On the other hand, direct-band-gap-engineered semiconductor nanostructures show high potential for the emission of prompt photons due to quantum confinement. In particular, the potential of materials based on semiconductor quantum dots/quantum wells such as CdSe, InGaN/GaN or perovskite nanocrystals (eg. XPbBr3) as scintillator or charged particle tracking for HEP detectors will be explored.