Advances in flexible optoelectronic devices have led to an increasing need for developing highly efficient, low-cost, flexible transparent conducting electrodes. Copper-based electrodes have been unattainable due to the relatively low optical transmission and poor oxidation resistance of copper. Here, we report the synthesis of a completely continuous, smooth copper ultra-thin film via limited copper oxidation with a trace amount of oxygen. The weakly oxidized copper thin film sandwiched between zinc oxide films exhibits good optoelectrical performance (an average transmittance of 83% over the visible spectral range of 400–800 nm and a sheet resistance of 9 Ω sq−1) and strong oxidation resistance. These values surpass those previously reported for copper-based electrodes; further, the record power conversion efficiency of 7.5% makes it clear that the use of an oxidized copper-based transparent electrode on a polymer substrate can provide an effective solution for the fabrication of flexible organic solar cells.

Nature Communications 6, Article number: 8830 doi:10.1038/ncomms9830
Received 14 July 2015 Accepted 07 October 2015 Published 05 November 2015

http://www.nature.com/ncomms/2015/151105/ncomms9830/full/ncomms9830.html

柔性电子器件的发展使得对高效、低成本、柔性透明电极的需求日益增加。铜基电极因其较低的光透过率和较差的抗氧化性而很难做成电极。 Zhao 等人通过对铜进行轻度氧化，制备了一种完全连续的、光滑超薄铜膜。铜薄膜夹在两层氧化锌薄膜中间，整个薄膜展示出 83% 的可见光透过率、 9Ωsq-1 的表面电阻以及强的抗氧化能力。这些特性超过了以往报道的铜基电极。他们将这种铜基电极用于柔性有机太阳能电池中，电池的效率达到 7.5% 。（新材料在线）