Lattice influence on the excited state relaxation

We study optical properties of two sets of alkali halide crystals, one with a uniform anion, the other with a uniform cation in the lattice, both the sets are doped with divalent lead. Great care is taken to complete or to improve the results so far published. The observed tendency in absorption and emission properties is discussed for both the sets. We connect the changes in the lifetimes of slow components and their actual course to changes in local bonding within the impurity centre.