May 30, 2013
Silver nanowire network optimized for use as transparent electrode
Silver nanowire (Ag NW) networks are one of the most competitive non-oxide based transparent conductors, but a few challenges remain concerning i) the residual polymer layer due to synthesis protocols and ii) high roughness. In recent work, researchers from Middle East Technical University, Ankara, Turkey, have provided insights into these issues and describe a cohesive approach involving a short annealing and planarization treatment. The networks were then used as anode structures in PLEDs, outperforming a control device fabricated on indium tin oxide (ITO).
For Ag NW networks to be used in light emitting diodes (OLEDs), market demands for transparent conductors must be met for all aspects including surface roughness. In this work, the high roughness value associated with as-deposited Ag NW networks was minimized through the infiltration of a conducting polymer, PEDOT:PSS, which is readily used for the hole injection layer in OLEDs.
OLEDs were then fabricated using this composite layer, formed with Ag NW networks and PEDOT:PSS, as anodes. The emissive layer of the OLEDs comprised MEH-PPV. In testing, it was revealed that electrical and optical behaviour of the OLED devices with Ag NW networks outperformed a control device fabricated on commercially available ITO anode, especially at higher operating voltages.
Full details can be found in the journal Nanotechnology.
About the author
The work was performed in the Department of Metallurgical and Materials Engineering at Middle East Technical University by researchers from the Nanomaterials and Devices Group led by Prof. H Emrah Unalan. The group is focused on the synthesis and solution processing of semiconducting and metallic nanowires and exploiting their novel properties in flexible devices. This particular work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) and Turkish Academy of Sciences (TUBA).