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Herein, we report the details of the synthesis and crystal growth of a lead-free perovskite derivative Cs2TeI6 crystal, which reveals long-term environmental stability. The synthesis process is optimized to obtain pure Cs2TeI6 polycrystals, and to eliminate the formation of residual CsI resulting from high vapor pressure. Subsequently, the Cs2TeI6 single crystal with dimensions of Φ10 mm × 55 mm is grown by the vertical Bridgman method. The as-grown 0-D structural Cs2TeI6 crystal exhibits a high resistivity of 9.92 × 1011 Ω cm, and resulting mobilities of 4.03 ± 0.33 cm2 V−1 s−1 and 9.40 ± 0.45 cm2 V−1 s−1 for electrons and holes, respectively. The Au/Cs2TeI6/Au device shows a good response for optoelectronic and X-ray detection, with a relatively high X-ray sensitivity of 27.8 μC Gy−1 cm−2 and a low detection limit of 72.5 nGy s−1. [ABSTRACT FROM AUTHOR]

ZnO:Ga (GZO), as well as other band-edge luminous materials, exhibits fast time response properties, which makes it suitable for application as an ultraviolet scintillator for transient radiation detection. However, due to the serious self-absorption problem and low external quantum efficiency, the luminescence intensity cannot be intensified by increasing the volume of the crystals. To alleviate this problem, CsPbBr 3 quantum dot (QD) films were used to enhance the radioluminescence (RL) intensity of GZO. The effects of CsPbBr 3 QD films on the emission spectrum, intensity and angular distribution were experimentally analyzed under three different modes, namely, coating on the imaging surface, incident surface and both surfaces. The CsPbBr 3 QD film on the imaging surface could change the external quantum efficiency and luminescence angular distribution of GZO via its various surface morphologies. When CsPbBr 3 QD films were coated on both surfaces, the luminescence intensity reached 2.43 times that of GZO, while the proportion of emitted light from GZO was less than 6 %. Based on the experimental results, the principle of the enhancement and the difference among the three coating modes were discussed. The enhancement caused by CsPbBr 3 QD films on GZO was considerable and could be simply duplicated on many other materials, expanding their application in the field of detection and imaging. • Radioluminescence intensity of ZnO:Ga can be enhanced by coating perovskite films. • Scintillation performance of CsPbBr 3 QD film-coated ZnO:Ga was investigated. • Tuning the angular distribution by CsPbBr 3 QD film is beneficial for X-ray imaging. [ABSTRACT FROM AUTHOR]