ST-401塑料闪烁薄膜的发光性质及其改性研究

Photoluminescence properties and modification of ST-401 plastic scintillator film

通过旋涂法制备了ST-401塑料闪烁薄膜。与塑料闪烁块体相比,薄膜的发射谱中出现了345nm附近的发射带和397nm处肩峰。随着薄膜厚度的减小,325～390nm范围内的激发谱归一化强度逐渐降低。染料POPOP的不同激发态有着不同的猝灭浓度,其中第一激发单重态的猝灭浓度较低。相对于同样厚度的ST-401薄膜,当第二发光物质POPOP在ST-401中浓度达到0.124wt.%时,发射谱在420nm处的荧光强度提高了约74.3%,这样薄膜可以更好地运用在飞行时间(TOF)系统中。

ST-401 plastic scintillator films were prepared by spin coating technique. As compared to the emission spectrum of plastic scintillator bulk, the band with a maxima at 345nm and the emission shoulder located at 397nm appeared in plastic scintillator film. In comparison with the excitation spectrum of plastic scintillator bulk, there is weak excitation intensity in the region of 325nm to 390nm of the plastic scintillator film relatively. For dye POPOP, different excited states have different quenching concentrations, and the first excited singlet state is lower than the second and third excited singlet state. As compared to the equal thickness of ST-401 film, photoluminescence intensity of the modified film at 420nm increased about 74. 3~/oo when the concentration of POPOP reached 0. 124wt. % in the scintillator film, which makes the films have a promising applicatioh in the time of flight （TOF） system.