Charge transport in random organic photoconductors

Electrophotography, the technology of modern photocopiers, is the only area in which the photoelectronic properties of organic materials are exploited on a large‐scale industrial basis. Neither crystalline nor polycrystalline materials can meet the requirements set by current designs, and polymers are obvious candidates. However, these need to be improved by controlling (or eliminating) the charge‐carrier trapping and by understanding how their morphology and disorder affect charge transport. Recent work on the photoconductivity of organic solids is described, indicating that although progress has been made much remains to be done.