Silver Transparent Electrodes Using Micro-Patterns Prepared from Polystyrene Colloidal Arrays

With the significant growth of the industry for electronic and optoelectronic devices such as touch screens, thin film solar cells, and light emitting device displays, the demands for transparent conductive electrodes have been increasing. However, conventional transparent electrodes are fabricated using expensive and complicated techniques, such as photolithography, sputtering deposition, and thermal evaporation. In this work, we propose a facile and cost-effective method to fabricate a new type of transparent electrode, using silver nanocrystals and micro-patterned structures. The micro-patterns were fabricated by solution processing with silica sol combined with soft lithography, using polydimethylsiloxane replica molds prepared from polystyrene colloidal arrays. Silver transparent electrodes were subsequently fabricated by deposition of silver nanocrystals onto the micropatterns, followed by sintering and selective etching. The optical transparency and sheet resistance of the electrodes were dependent on the size of micro-patterns. The optimal electrode produced using a 2-μm pattern, showed outstanding optical and electrical properties with a transmittance of ~80% throughout the visible range and a sheet resistance of 60 Ω/sq. This novel silver transparent electrode can be an excellent candidate for electronic applications.