Charge Carrier Dynamics of Halide Perovskite Nanocrystals: Application Toward X-Ray/Gamma-Ray Radiation Detection

Recently, metal halide perovskites (MHPs) with the general chemical formula ABX3 (where A=Cs+, methylammonium (MA+), formamidinium (FA+); B=Pb2+; X=I−, Br−, Cl−) have emerged as a new class of materials for application in solar energy harvesting, scintillation X-ray/gamma-ray photon counting, and light-emitting diodes (LEDs). This class of materials with versatile chemical properties and structural dimensionality (referred in literatures as 3-D, 2-D, 1-D, 0-D perovskites) has a few unique attributes, including high charge carrier mobility, long carrier lifetime, high defect tolerance, low density of trap states, large bulk crystal semiconducting resistivity, and low materials synthesis cost using the solution-processing methodology. In this chapter, halide perovskite nanocrystals will be introduced and the application of perovskite nanocrystals for scintillation radiation detector counting (X-ray and gamma-ray) will be discussed. Charge carrier dynamics of electrons and holes from excitation to carrier recombination (i.e., the scintillation light-emitting mechanism) will be briefly introduced. In the meantime, readers will be referred to the previous discussion of perovskite single crystals as semiconductors rather than scintillators for X-ray and gamma-ray ionizing radiation detection.