Scintillation activated by nanoparticle formation in CsI:Na thin films

• Published in: Journal of luminescence Vol. 108; no. 1; pp. 359 - 363
• Main Authors: Nakayama, M., Ando, N., Hirai, J., Nishimura, H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-06-2004; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; CsI:Na; Exact sciences and technology; Insulators; Nanocrystals and nanoparticles; Nanoparticle; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Optical properties of specific thin films; Physics; Scintillation; Self-trapped exciton; 71.35.Aa; 78.55.Fv; 78.20.−e; Nanoparticle; Scintillation; CsI:Na; Self-trapped exciton; Scintillations; Atomic force microscopy; Self trapping; Surface morphology; Doping; Luminescence; Cesium iodides; Experimental study; Heat treatments; Sodium iodides; Thin films; Nanoparticles; Excitons; Temperature effects; 78.20:-e CSI:Na; Optical properties; Excitation spectrum; Energy transfer; Vacuum deposition
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2004.01.076

The scintillation mechanism in Na-doped CsI (CsI:Na) crystalline thin films grown by vacuum deposition has been investigated from the aspects of optical and structural properties. It is found that a heat treatment of the thin film activates the Na-related luminescence corresponding to the dominant scintillation in a CsI:Na crystal. The surface morphology of the thin films measured by atomic force microscope demonstrates that the heat treatment causes the formation of nanoparticles. From the excitation spectrum of the Na-related luminescence and the temperature dependence of the luminescence properties, it is concluded that the scintillation of CsI:Na is caused by the energy transfer from the host material of CsI to NaI nanoparticles.