Light welding nanoparticles: from metal colloids to free-standing conductive metallic nanoparticle film
Fei Chen, Shuzhen Yang, Zhenjun Wu, Wei Hu, Jiawen Hu, Xiangfeng Duan
Sci. China Mater. 60, 39-48 (2017)
Bottom-up assembly of nanostructured thin films could offer an alternative low-cost approach to electronic thin films. However, such solution-processed thin films are often plagued by excessive inter-particle resistance and only exhibit limited current delivering capability. Here, we report a novel approach to fabricate highly conductive free-standing metallic thin film, accomplished by combining interfacial self-assembly of nanoparticles (NPs) and a light welding process. We found that light from a xenon lamp can weld adjacent Ag and Au NPs assembled at the water-air interface, forming a highly interconnected, free-standing metallic thin film structure with excellent electrical transport properties. With such a unique structure, the resultant thin metallic films show not only high flexibility and robustness, but also high conductivity comparable to bulk metallic thin films. Our studies offer a low-cost, room-temperature, and solution-processable approach to highly conductive metallic films. It can significantly impact solution-processable electronic and optoelectronic devices.