High-Speed Epitaxial Growth of Terbium- and Europium-Doped Yttrium Aluminum Perovskite Thick Film Phosphors Using Laser-Assisted Chemical Vapor Deposition

Abstract

A thick film scintillator with a few tens of micrometers thickness is expected to improve sensitivity and spatial resolution in radiation detection and imaging, while its production method is limited to a costly process of thinning a melt-grown single crystal ingot. Here, we demonstrated the high-speed epitaxial growth of terbium- and europium-doped yttrium aluminum perovskite (Tb³⁺:YAP and Eu³⁺:YAP) transparent thick film phosphor using laser-assisted chemical vapor deposition (CVD). The (110)-oriented YAP thick film was epitaxially grown on a (100) SrTiO₃ (STO) substrate. The deposition rate was 53 µm h⁻¹, which was 50–90 times faster than those reported for conventional thermal CVD. Under UV and X-ray irradiation, the films emitted green and orange lights originating from 4f → 4f transitions of Tb³⁺ and Eu³⁺ centers, respectively. The fluorescence decay curves of the films were fitted to 1.96 and 1.89 ms for Tb³⁺ and Eu³⁺ centers. The 9 µm-thick Eu³⁺:YAP thick film phosphor can be used as a scintillation screen of X-ray imaging test to see though a semiconductor storage device.