Growth mechanism of silver nanowires by polyol process and their application for transparent conductive thin film

• Main Authors: Liang-zheng hong, 洪良政
• Other Authors: Hsun-Feng Hsu
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/36439396990526488237

碩士 === 國立中興大學 === 材料科學與工程學系所 === 103 === One-dimensional nanowires have attracted intense interest due to their unique photo-electric, magnetic and thermal conductive characteristics. Silver nanowire based thin films have been recently used as transparent conductive films because of their high optical transparency, low sheet resistance and flexibility. Previous studies have demonstrated that polyol process, one of widely used method for Ag NWs chemical synthesis, could be used to produce silver nanowires by adding Cl- ions with appropriate concentration in the process. Besides Ag nanowires, Ag particles could also be formed with addition of much higher or lower Cl- ions. However, optimal reaction time and concentration of Cl- ions for Ag nanowires synthesis have rarely been reported. In this study, Ethylene Glycol(EG) solution with AgNO3 was prepared and added in EG solution with Polyvinylpyrrolidone (PVP) for Ag nanowire formation. Mechanism of Ag nanowire formation was investigated by adding different amount of NaCl for different reaction time. According to the results, Ag nanoparticles were initially formed and gradually turned into nanowires because of PVP addition. However, AgNWs would gradually shorten while growing at critical length in the reaction. This interesting phenomenon could be explained by the concentration of Ag nanowires and their surface energy. Furthermore, the longest Ag nanowires could be obtained under condition of optimal reaction time and concentration of Cl- ions. These Ag nanowires were prepared as transparent conductive thin films for optical transmittance and electrical conductivity measurements. Ttransparent conductive thin films with long AgNWs have better conductivity than short ones, and their stability would be further increased while coating the Polymethylmethacrylate (PMMA) as protective layer.