This paper presents new developments in inorganic scintillators widely used for radiation detection. It addresses major emerging research topics outlining current needs for applications and material sciences issues with the overall aim to provide an up-to-date picture of the field. While the traditional forms of scintillators have been crystals and ceramics, new research on films, nanoparticles and micro- structured materials is discussed as these material forms can bring new functionalitiy and therefore find applications in radiation detetction. The last part of the contribution reports on the very recent evolutions of the most advanced theories, methods and analyses to describe the scintillation mechanisms.

Properties of praseodymium and cerium doped Lutetium Aluminum Garnet (LuAG) were compared with cerium doped Lutetium Oxyorthosilicate (LSO) and Lanthanum Bromide (LaBr ₃ ). Light yield, its non-proportionality relative to 662 keV gamma -rays and the dependence of the energy resolution on energy of the detected gamma -rays were measured. LuAG:Pr turned out to have good proportionality, with deviation from unity around 10% at 16.6 keV and 3% at 59.5 keV. This, together with relatively high light yield of 5600 phe/MeV results in a very good energy resolution of LuAG:Pr of 5.1% measured with 662 keV gamma-rays. The measured time resolution of 308 ps is significantly larger than that of 166 ps obtained for LSO:Ce. This can be explained by smaller light yield of LuAG:Pr and the fact that only about 25% of its scintillation is emitted in short decay time modes of 17.6 ns and 52 ns, while the rest is decaying with long time modes of 1.4 mus and 9 mus.

We report the growth of bulk β-Ga₂O₃ crystals based on crystal pulling from a melt using a cold container without employing a precious-metal crucible. Our approach, named oxide crystal growth from cold crucible (OCCC), is a fusion between the skull-melting and Czochralski methods. The absence of an expensive precious-metal crucible makes this a cost-effective crystal growth method, which is a critical factor in the semiconductor industry. An original construction 0.4–0.5 MHz SiC MOSFET transistor generator with power up to 35 kW was used to successfully grow bulk β-Ga₂O₃ crystals with diameters up to 46 mm. Also, an original diameter control system by generator frequency change was applied. In this preliminary study, the full width at half maximum of the X-ray rocking curve from the obtained β-Ga₂O₃ crystals with diameters ≤ 46 mm was comparable to those of β-Ga₂O₃ produced by edge-defined film fed growth. Moreover, as expected, the purity of the obtained crystals was high because only raw material-derived impurities were detected, and contamination from the process, such as insulation and noble metals, was below the detection limit. Our results indicate that the OCCC technique can be used to produce high-purity bulk β-Ga₂O₃ single crystalline substrate.

The design of fluoride-based optical devices for deep ultraviolet applications is discussed. Variations in the band-gap energy and band structure with respect to composition are investigated for ${\mathrm{Li}}_{(1-x)}{\mathrm{K}}_x{\mathrm{Ba}}_{(1-y)}{\mathrm{Mg}}_y{\mathrm{F}}_3$ perovskites. The band-gap energy, lattice constant, and band structure of perovskitelike fluorides are estimated based on ab initio calculations within the local-density approximation. The lattice-matched double heterostructure with direct band-gap compounds (${\mathrm{Li}}_{(1-x)}{\mathrm{K}}_x{\mathrm{Ba}}_{(1-y)}{\mathrm{Mg}}_y{\mathrm{F}}_3$ on either $\mathrm{Li}\mathrm{Ba}{\mathrm{F}}_3$ or $\mathrm{K}\mathrm{Mg}{\mathrm{F}}_3$ substrates) is promising for fabrication.