Development and characterization of Ln3+-doped Gd2GeO5 phosphors

The Ln3+ (Ln3+ = Eu3+, Dy3+, Tb3+ or Sm3+)-doped Gd2GeO5 phosphors are produced by using the solid-state reaction. The Gd2GeO5 has a high effective Z-number (Z eff = 46) and density (7.12 g/cm3) and is sensitive to X-rays. The emission wavelengths of Ln3+-doped phosphors are expected adequate for the CCDs. We fabricated Ln3+-doped Gd2GeO5 phosphors and studied their structural and luminescence properties. The Ln3+-doped Gd2GeO5 phosphors were excited by ultraviolet (UV) light, X-rays, and protons. The emission wavelengths were measured to be from 450 nm to 750 nm. The 45-MeV proton beam at the MC-50 cyclotron in the Korea Institute of Radiological and Medical Sciences was used for this purpose. These emission wavelengths matched well with those for a typical CCD. Therefore, Ln3+-doped Gd2GeO5 phosphors are good candidates for use of radiation-imaging phosphors.