Recent R&D Trends in Inorganic Single-Crystal Scintillator Materials for Radiation Detection

In this review, the major achievements and research and development (R&D) trends from the last decade in the field of single crystal scintillator materials are described. Two material families are included, namely, those of halide and oxide compounds. In most cases, the host crystals are doped with Ce³⁺, Pr³⁺ or Eu²⁺ rare earth ions. Their spin- and parity-allowed 5d-4f transitions enable a rapid scintillation response, on the order of tens to hundreds of nanoseconds. Technological recipes, extended characterization by means of optical and magnetic spectroscopies, and theoretical studies are described. The latter provide further support to experimental results and provide a better understanding of the host electronic band structure, energy levels of specific defects, and the emission centers themselves. Applications in medical imaging and dosimetry, security measures, high-energy physics and the high-tech industry, in which X(γ)-rays or particle beams are used and monitored, are recognized as the main driving factor for R&D activities in this field. Major achievements and research and development trends in the last decade for the field of single crystal scintillator materials are described. Halide and oxide compounds are reviewed in detail. Several examples of successful compositional and defect engineering are provided, which have led to substantial improvements of scintillation characteristics and/or discovery of new material systems.