Influence of the humid air on the structure and fluorescent property of CsI:Tl thin film

CsI:Tl is a very efficient scintillator which is widely used in X-ray detection. However, it tends to deliquesce when exposed to the humid air. Thus, in this paper, we examined the change of the morphology, growth orientation and the fluorescent property of CsI:Tl thin film when it was exposed to the humid air with different humidity. It turned out that when CsI:Tl thin film was exposed to the humid air, its grain size became bigger, its preferential growth orientation changed and its light conversion property decreased.