Aleksandra Pajak, Marie-Andrée Dionne, Oleg Zabeida, Bill Baloukas, Jolanta Klemberg-Sapieha, Ludvik Martinu, Polytechnique Montréal, Montréal, Québec, Canada
New approaches in the development of transparent flexible electrodes (TFEs) are crucial for the next generation of more complex and faster organic optoelectronic devices. Transparent conductive oxides (TCOs) are some of the most common materials - especially tin-doped indium oxide (ITO), as it possesses high luminous transmittance (Tlum) and can reach low resistivity (ρ); however, due to its high brittleness, it has a limited applicability as a flexible conductor.
Herein, we are reporting the outlook onto hybrid-type thin film materials on polymer substrates which outperform current state-of-the-art TFEs and add additional level of their functionalization. Firstly, different combinations of materials, such as ITO, other TCOs and metals (e.g., Au, Ag, Cu), were deposited via physical vapor deposition (PVD), specifically magnetron sputtering. Subsequently, alternative methods allowing for the manufacture of TFEs with three-dimensional features, were investigated - especially those which can produce nanostructured surfaces allowing for an enhanced injection of electrons to the conduction band and can improve their transparency due to the antireflective effect. The optoelectrical performance of such TFEs was optimised to obtain Tlum greater than 80% and sheet resistance (RS) below 50 Ω □^-1, and tested for their deformability, adhesion and abrasion resistance.