Ionized States in a One‐Dimensional Molecular Crystal

Generalization of the theory of excitons in molecular crystals to include ionized states is carried out for an idealized one‐dimensional model for which the exact wave functions and energy levels can be derived. The ionized states are found to form a progression of bands corresponding to bound states of the electron and hole. The bound levels converge to a band of free states in which the electron and hole move independently and can carry an electric current. The lowest‐lying ionized states may interact significantly with the un‐ionized molecular exciton states and give rise to weak charge‐transfer absorption bands.