Controlling the aspect ratio of silver nanowires in the modified polyol process

Metal nanowire-based conducting networks, primarily based on silver nanowires (Ag NWs), show promise for flexible transparent conducting electrodes. The synthesis of high aspect ratio Ag NWs is the key to accomplishing good optoelectronic performance. Among the various synthesis routes available, the one-pot polyol method is widely used. It is based on the reduction of silver nitrate (AgNO3) by a polyol, typically ethylene glycol, in the presence of polyvinylpyrrolidone (PVP) and ferric chloride. The present work provides a systematic study of the role of PVP to AgNO3 weight ratio on the physical dimensions (length, diameter, and aspect ratio) of the Ag NWs and the role of NW concentration and spin coating speed on the optoelectronic properties (transparency and conductivity) of the NW-based network.