Diffusion of Color Centers into KBr-Tl Phosphors

Abstract

The diffusion of color centers into a KBr-Tl phosphor has been investigated during a coloring process in potassium vapor. Proceeding from the surface to the interior of the crystal, F-centers, complex centers, and Tl neutral centers were observed successively. The boundary between the crystal region containing these centers and the rest of the crystal containing only Tl⁺ ion centers was very distinct. The depth of the front surface of diffusing Tl neutral centers was proportional to the square root of exposure time. Complex centers were composed of a Tl neutral center, a negative ion vacancy and an electron.