Researchers from the Max-Planck-Institute for Polymer Research (MPI-P) have built upon new understanding on organic electronic material defects to suggest ways to design higher efficiency OLED materials.
The researchers explain that they have discovered that clusters of water inside organic semiconductors can function as hole traps, and oxygen clusters can capture electrons in hole-dominated organic semiconductors. Even a small number of such water and oxygen defects can cause highly unipolar charge transport and harm the efficiency of the materials.
Removing such defects in materials is very challenging - but the researchers propose a different path - designing the materials in such a way that the influence of water and oxygen molecules are reduced. Based on this concept, the first highly efficient OLEDs with defect-free electrical conduction have recently been realized.