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Dr. Regine Kleber and

María García

infoEzw8∂heika-research de

Functionalized tetraazapentacenes as electron-transport materials for multi-layer OLEDs

Functionalized tetraazapentacenes as electron-transport materials for multi-layer OLEDs

Dr. Felix Peter Hinkel, Centre for Advanced Materials, University of Heidelberg

Dr. Philip Scharfer, Institute of Microstructure Technology, KIT


Organic Electronics






The goal of our HEiKA project was to find electron transport layer (ETL) materials suitable for multi-layer OLEDs according to the orthogonal solvent concept. Therefore, the material needs to be soluble in some solvents and insoluble in others. This is to prevent solvent penetration in a layer below and layer intermixing.
Tetraazapentazenes (TAPs) are electron-poor derivatives compared to the well-studied pentacene. The TAPs shows a lower lying LUMO energy level (ca. -3.5 eV) and are applicable as electron-transport materials (ETM). We adjust optical properties of mono-bromo TAP by chemical functionalization. We received a high amount of new compounds that are now under investigation. With the synthesized materials mass transport measurements are done using an ultraprecise sorption apparatus with a quartz crystal microbalance. The measurements show that it is possible to tune solubility by adding substituents and get ETL materials that fit the orthogonal solvent concept. Also we found a material/solvent combination with a profoundly increased solvent diffusion coefficient.