Development and challenges in perovskite scintillators for high-resolution imaging and timing applications

Inorganic scintillators play a major role in ionizing radiation detection due to their high versatility to detect multiple radiation sources such as X-rays, gamma-rays, alpha, beta, and neutron particles, and their fast and high light yield, making them especially convenient for imaging, spectroscopy, and timing applications. Scintillators-based detection systems are found, among various applications, in medical imaging, homeland security, high-energy physics, industrial control, oil drilling explorations, and energy management. This Review discusses advances and prospects of perovskite scintillators, particularly low-dimensional hybrid organic-inorganic perovskite crystals and all-inorganic perovskite nanocrystals. We highlight the promise of two-dimensional lithium-doped (PEA)₂PbBr₄ crystals and CsPbBr₃ nanocrystals as scintillators with high light yields, exceeding 20 photons/keV, and fast decay times of less than 15 ns. Such a combination may result in fast-spectral X-ray imaging, an output count rate exceeding 30 Mcps/pixel in photon-counting computed tomography, and coincidence timing resolution of less than 100 ps in positron emission tomography. We review recent strategies to further improve light yield, decay time, and coincidence timing resolution through light-matter interactions such as extraction efficiency enhancement and Purcell-enhanced scintillators. These advancements in light yields and decay times of perovskite scintillators will be particularly useful in the medical and security applications.