Enhanced luminescence of CuI thin film scintillator by reducing Fresnel reflection

摘要

CuI thin film scintillator has potential applications in radiation detection systems due to its fast component of luminescence. Severe Fresnel reflection due to its large refractive index decreases its external quantum efficiency. In this article, we design an antireflection coating of SiO_2 to efficiently eliminate Fresnel reflection and thus improve luminescence intensity. The optimal thickness of coating aimed at the maximum transmission for the omni-directional integration is obtained. The reduced Fresnel reflection by the antireflection coating is based upon the gradient-index and the interference effect. The luminescence intensity with an antireflection coating is increased by 20% at the emission peak wavelength.