Mr. Basel Shamieh, Ph.D. Candidate
Department of Materials Science and Engineering,
Technion – Israel Institute of Technology Haifa 3200003, Israel
Efficiency of charge transfer across the organic/metal interface is seminal in all organic electronic devices, and is directly linked to their performance. Adjusting the effective work function at the metal/organic interface, therefore, is crucial for imposing/eliminating barriers for charge extraction/injection, reducing contact resistance and controlling charge recombination. This is generally achieved by an independent fabrication step for producing ultrathin organic or inorganic films, between the active layer and the electrode. The composition and interactions imposed by the interlayer affect the electronic properties of the components, and determine the energy level alignment at the interface and the efficiency of the device. In this work, we present the spontaneous and concurrent formation of cathodic and anodic interlayers in organic solar cells (OSC), and their effect on various properties of the organic/electrode interface. To direct the migration of additives towards specific interfaces, we rely on physical principles of phase separation such as surface energy and chemical affinity. The self-organization of both continuous and ultrathin organic interlayers not only spares independent processing steps but also improve the device performance, its thermal stability and ambient lifetime which are crucial for real-life application of organic solar cells.