Polarization Studies on Recombination Luminescence in a Rigid Organic Solution

Abstract

Polarized photoselection techniques are applied to stimulated recombination luminescence in a rigid organic solution at 77°K. Ionization with polarized ultraviolet light leads to an oriented sample of solute cation and electrons trapped in the matrix. Infrared light stimulates the recombination of the electrons with the oriented population of cations giving a recombination luminescence whose polarization characterizes the orientation of the cations. Two interpenetrating populations of cations are produced sequentially using perpendicular polarization directions for the ionizing light. Recombination emission from the two populations may be distinguished by their differing polarization, and it is found that the electrons ejected in the ionization of one population do not recombine with the cations of the other. These results are examined in some detail. It is concluded that in the majority of ionization and recombination events, each electron remains highly correlated with its site of origin.