Enhancement of the luminescence intensity of a ZnO:Ga crystal scintillator via coating CsPbBr3 quantum dot films

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, CsPbBr3 quantum dot (QD) films were used to enhance the radioluminescence (RL) intensity of GZO. The effects of CsPbBr3 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 CsPbBr3 QD film on the imaging surface could change the external quantum efficiency and luminescence angular distribution of GZO via its various surface morphologies. When CsPbBr3 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 CsPbBr3 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.