Research on properties of commonly-used phosphors for low-level-light image intensifiers

The phosphors is the key material of the fluorescent screen of low-level-light image intensifier, which can transform the electronic images into the visible optical images. Its performances have an important influence on the resolution, luminescence spectrum, modulation transfer function and afterglow of the image intensifier. In view of the current development of image intensifier at home and abroad, a comparative performance study was carried out on the commonly-used P20 ((Zn, Cd) S: Ag), P22 (ZnS: Cu, Al), P31 (ZnS: Cu), P43 (Gd₂O₂S: Tb) and P45 (Y₂O₂S: Tb) for fluorescent screen of image intensifier. The phase structure, spectral characteristics, luminous efficiency and resolution of these five types of phosphors were characterized respectively, and the applicable conditions of different kinds of phosphors were analyzed. The results show that these five types of commonly-used phosphors contribute to the improvement of different performances of image intensifier. Among which, the P43 phosphors has higher resolution, the P22 phosphors has higher luminous efficiency, and the P45 phosphors provides the best observation comfort for the human eyes. In view of the requirements for the high performance of the low-level-light image intensifier, the P22 and the P43 phosphors with superior comprehensive performance can be selected when selecting phosphors for the low-level-light image intensifier, and the appropriate types of phosphors can also be selected according to the specific performance requirements and actual use requirements of image intensifier.