Research | Dept. Blom
Understanding and optimizing the operation of devices based on organic semiconductors by manipulating charge-, energy- and ion transport on the molecular scale. Utilizing the full feedback loop from synthesis to device fabrication, structuring, electrical, optical and morphological characterization.
The fact that organic semiconductors can be processed from solution raised an enormous research interest in both academia and industry. Application of printing technology was expected to lead to a paradigm shift in the production of displays and large-area devices as lighting tiles and solar cells. However, with regard to organic light-emitting diodes (OLEDs) the efficiency criteria for commercialization have only been met by the application of complex multi-layer device architectures, obtained by vacuum deposition. In such a multilayer structure processes as charge injection, charge transport and emission are individually optimized in at least five different organic layers, each with their own functionality. Simultaneous optimization of all these processes in just one single solution-processed layer has been deemed impossible and further efforts in this direction were abandoned. Here, a major issue is that many of the measured electronic properties of solution-processed organic semiconductors are not intrinsic, but masked by defects that act as charge traps or exciton quenchers. With regard to functional polymers a unique property is their ability to form controllable structures when blended with other polymers. By doing so, their functionality can be altered or even new properties can be created, depending to what extend the polymers will phase separate. Controlling the morphology of polymer-based structures on the nanometer scale to manipulate charge-, energy- and ion transport is our main objective. The research focus of the department can be represented by 4 interlinked activities: