"A transparent electrode based on a metal nanotrough network"

Hui Wu: Desheng Kong, Zhichao Ruan, Po-Chun Hsu, Shuang Wang, Zongfu Yu, Thomas J. Carney, Liangbing Hu, Shanhui Fan & Yi Cui; Nature Nanotechnology, 05/19/13.

Additional Authors: Desheng Kong, Zhichao Ruan, Po-Chun Hsu, Shuang Wang, Zongfu Yu, Thomas J. Carney, Liangbing Hu, Shanhui Fan & Yi Cui

Abstract:

Transparent conducting electrodes are essential components for numerous flexible optoelectronic devices, including touch screens and interactive electronics1, 2, 3, 4. Thin films of indium tin oxide—the prototypical transparent electrode material—demonstrate excellent electronic performances, but film brittleness, low infrared transmittance and low abundance limit suitability for certain industrial applications1, 4, 5. Alternatives to indium tin oxide have recently been reported and include conducting polymers6, carbon nanotubes7, 8, 9 and graphene10, 11, 12. However, although flexibility is greatly improved, the optoelectronic performance of these carbon-based materials is limited by low conductivity8, 13. Other examples include metal nanowire-based electrodes14, 15, 16, 17, 18, 19, 20, 21, 22, which can achieve sheet resistances of less than 10Ω □−1 at 90% transmission because of the high conductivity of the metals. To achieve these performances, however, metal nanowires must be defect-free, have conductivities close to their values in bulk, be as long as possible to minimize the number of wire-to-wire junctions, and exhibit small junction resistance. Here, we present a facile fabrication process that allows us to satisfy all these requirements and fabricate a new kind of transparent conducting electrode that exhibits both superior optoelectronic performances (sheet resistance of ~2Ω □−1 at 90% transmission) and remarkable mechanical flexibility under both stretching and bending stresses. The electrode is composed of a free-standing metallic nanotrough network and is produced with a process involving electrospinning and metal deposition. We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape.