The goal of the project is to develop methods for modification of silver electrode work function using a series of perylene diimide (PDI) derivatives, which, properly designed, can be used to alter not only the silver electrode work function, but also other commonly used electrodes such as indium tin oxide (ITO). This modification can occur through the introduction of an ultra-thin layer (<10 nm) of PDI-based material between the electrode and the active layer. Regardingthe synthesis of new materials, the project is based on the three concepts: (1) the synthesis of perylene diimide derivatives equipped with polar functional groups, serving as an anchor for the electrode surface and efficiently modifying its work function, (2) the use of the new perylene diimides as dispersants of graphene flakes in order to produce a composite that efficiently modifies electrode work function, (3) the development and obtainment of perylene diimide PDI-based systems forming well-organized 3D structures.

The second goal of the project is to understand the mechanism of action of the implemented interlayers by applying comprehensive physical and electrical studies, including measurements of their work function, relationship between ability to modify the work function of the electrodes and their chemical structure, and testing the interlayers in metal-semiconductor systems. Studies on the efficiency of electrode work function modification will be tested in photodiodes and light-emitting diodes, which architecture will be designed with taking into account the parameters of the developed electrode-interlayer systems (work-function ability to inject or block charge carriers). Interlayers used in fabricated optoelectronic devices will be prepared by the means of inkjet printing technique from appropriately developed ink, using a laboratory printer. The analysis of the obtained results will be supported by a properly selected simulation model (the drift-diffusion method), which will help in the identification of physical phenomena occurring at the electrode-interlayersemiconductor interface, and to improve the operating parameters of the produced optoelectronic devices.