Ion beam induced luminescence in ion implanted CaF2

CaF2 single crystals are relatively hard to be damaged by ion irradiation at acceleration energy of 100 keV and 1016 ions/cm2, and it was observed that in the implantation of rare earth ions, Eu+ or Tb+, the color of light emitted from the target CaF2 depended on the kinds and amount of implanted ions. When Eu+ was implanted, while the amount of implantation was small, the light emission at 430 nm (blue) by Eu2+ was strong, and from 1015 ions/cm2, the light emission from Eu2+ rapidly decreased, and the light emission at 600 nm (orange) from Eu3+ rapidly increased. When Tb+ was implanted, with the increase of amount, the spectra of light emission changed from 380 nm to 545 nm (green) in wavelength, but all from Tb3+. The obtained wavelengths of light emission, 430, 545 and 600 nm, are close to three primary colors of light, therefore, by the double implantation of Eu+ and Tb+ by respective proper amounts in CaF2 single crystals, white light emission was tried. Moreover, it was known that in the RBS process using channeling together, the crystallinity in the implanted layer was relatively good, and the considerable amount of the implanted ions entered the lattice positions even at room temperature. The experimental method and the results of the optical properties and the results of the RBS measurement using channeling together are reported. (K.I.)