In the last two decades the field of organic electronics has strongly expanded. A major scientific issue is the mechanism of charge transport and recombination in organic semiconductors. We focus especially on the effects of molecular structure, charge carrier density, and impurities in organic devices. Recently, by incorporating the role of impurities in the recombination the operation of organic light-emitting diodes and organic photovoltaic devices has been consistently described. In 2005 the first organic memory device based on polymeric ferroelectrics was developed, followed in 2008 by a new type of two-terminal memory device and electronic switch. By using self-assembly molecular diodes were constructed of which the active part consists out of only one monolayer of functional molecules. We recently realized transistors and complete integrated circuits using a self-assembled monolayer of molecules as active layer This result is now considered as the first ever true demonstration of ‘bottom-up electronics’. Future research will focus on directed self-assembly of organic components.