Theory of charge carrier production in photoconducting molecular crystals

Many of the crystals of organic compounds are molecular crystals, which are aggregates of a large number of perturbed molecules (perturbed by the neighboring molecules). In such crystalline states molecules keep their identity while bound to each other through weak attractive forces. Among such crystals are the pure crystals of aromatic compounds, typically polyacenes, Even though these molecular crystals are essentially insulators, the electrical current can be increased a thousandfold by irradiating with ultra violet light in the fundamental absorption region.