text: Scintillation properties of organic-inorganic methylamonium (MA) lead halide perovskites under proton irradiation were first reported by Shibuya et al. in 2002  and the first γ-ray pulse height spectrum, although still with poor energy resolution, was reported on () by van Eijk et al. in 2008 . Birowosuto at al.  studied the scintillation properties of 3-D and 2-D layered perovskites under X-ray excitation. MAPbBr () emits at 550 nm and MAPbI () at 750 nm which is attributed to exciton emission near the band gap of the compounds. In this first generation of Pb-halide perovskites the emission is strongly quenched at room temperature and less than 1 000 ph/MeV survive. At 10 K however intense emission is observed and  write about yields up to 200 000 ph/MeV. The quenching is attributed to the small e-h binding energy in the exciton that decreases for Cl to Br to I . Interestingly one may replace the organic MA group with Cs+ to obtain full inorganic CsPbX halide perovskites. Depending on the Cl, Br, I content the triplet X-ray excited exciton emission can be tuned from 430 nm to 700 nm . One may also dilute Cs with Rb to obtain similar tuning. Above very recent developments demonstrate that the organic-inorganic and all inorganic Pb-halide perovskites have various interesting scintillation properties. However, the recent two-dimensional perovskite single crystals with light yields between 10 000 and 40 000 ph/MeV and decay times below 10 ns at room temperature  will be more favorable as they may have much larger Stokes shift up to 200 nm in comparison with CsPbBr quantum dot scintillators and this is essential to prevent self reabsorption for scintillators.
  More recently, a new material class first reported by Professor [https://www.chem.fsu.edu/~ma/ Biwu Ma's] research group, called 0D organic metal halide hybrid (OMHH), an extension of the perovskite materials. This class of materials exhibits strong exciton binding of hundreds of meV, resulting in their high photoluminescent quantum efficiency of almost unity. Their large stoke shift and reabsorption-free properties make them desirable. Their potential applications for scintillators have been reported by the same group, and others. In 2020,(C38H34P2)MnBr4 was reported to have a light yield up to 80 000 Photon/MeV despite its low Z compared to traditional all inorganic. Impressive light yields from other 0D OMHH have been reported. There is a great potential to realize new generation scintillators from this material class. However, they are limited by their relatively long response time in microseconds, which is an area of intense research.