The field of organic semiconductors has seen much development in the past years. Displays based on light-emitting diodes made of small organic molecules as well as polymers, have recently been commercialized. Other applications, such as electronic circuits for tagging, efficient photovoltaic devices and biosensors, have already been demonstrated. This volume brings together a "wish list" of leading researchers in the fields of chemistry, physics and technology of organic devices. Novel device concepts such as charge-generation layers, metal complexes and the use of heterojunctions are presented and should lead to further improvement in the efficiency of organic light-emitting diodes. In the field of organic transistors, major progress is reported on the charge-transport properties of organic semiconductors; mobilities up to 5cm2/Vs are reported for pentacene-based transistors. High mobility n-type materials, which enable the development of ambipolar organic electronic circuits, are also discussed. And new approaches to fully printable displays on substrates, such as textiles and paper, are presented. These may lead the way to new applications of organic optoelectronic devices.