| 초록 |
Recently, the significant technical demand for cost-effective, highly conductive printable materials has increased in various fields of printed optoelectronic applications. In order to realize these requirements, printable metallic electrodes with solution-processability, high electrical conductivity, low-temperature processability, and environmental stability are inevitably necessary. A variety of conducting materials, such as organometallic precursors, conductive polymers, and metallic nanoparticles (NPs), have been widely studied as alternative electrodes. For example, Ag NPs with high conductivity have been used as electrode prepared by photonic sintering process that utilize a flash irradiation of white light. However, the particular issue of the material cost of silver has been increasingly addressed and considerably limited its practical and industrial applications. Here we report a highly effective strategy to improve the chemical resistance of the Cu NPs-based electrode by coating the Ni protective shell on the surface of the Cu NPs. The electrical resistance and resistance to oxidation of the Cu@Ni electrodes could be precisely controlled by adjusting the thickness of the Ni shell layer and modulating the light intensity during flash photonic sintering. The photo-sintered Cu@Ni electrodes exhibited high conductivity under optimal photonic sintering and provided long term oxidation stability even under a humid ambient atmosphere at an elevated temperature. In addition, we demonstrated a flexible and printable heater based on Cu@Ni NPs with a much broader operating temperature range (up to 200 oC) compared to that prepared by pure Cu NPs, which allows great opportunities for next-generation wearable electronics or automobile applications. |
