CHARGE-TRANSFER EXCITATIONS OF DOPED RARE-GAS MATRICES

Structured progressions, associated with the Cl-Rg+ and H-Rg+ charge transfer species, are observed for Cl and H atoms isolated in Kr and Xe (Rg) crystals and are assigned as transitions to Rydberg states. The Rydberg levels correspond to delocalized positive hole states in the rare gas solid (Rg+) orbiting a negative centre (Cl- or H-). For OH in Ar and Kr matrices, transitions to static charge transfer states are identified. For both of these rather extreme situations, simple models are used successfully to predict the transition energies. For the former, an exciton model based on the effective mass approximation and utilizing quantum defect numbers is used, while in the latter, a Coulombic potential screened by the medium is used.