High-performance Large-scale Flexible Optoelectronics using Ultra-thin Silver Films with Tunable Properties.

One key obstacle in fabricating efficient flexible and printable optoelectronic devices is the absence of ideal flexible transparent conductors with superior optical, electrical, and mechanical properties. Here, high-performance flexible transparent conductors are demonstrated using ultra-thin (< 10 nm) doped silver films, which exhibit an averaged visible transmittance of 80% without any anti-reflection coating, sheet resistance less than 20 Ω Sq-1, and mechanical stability over 1000 bending cycles. The conductor is prepared by doping silver with an additive metal (e.g., nickel, copper, titanium, chromium), and its various properties can be readily tuned by either using different doping metal species or controlling the dopant concentration. Centimeter-size, flexible polymer light emitting diodes are fabricated using a nickel-doped silver based electrode, and the devices exhibit 30% enhanced current efficiencies compared to their ITO counterparts, invariant emission spectra at large viewing angles, and operational stability over 1200 bending circles. In addition, 6-inch flexible low-emissivity coatings are demonstrated using a copper-doped silver based conductor, which transmit 85.2% of the visible light while reject over 90% of the infrared radiation beyond 1250 nm.