| Summary: | 碩士 === 國立成功大學 === 微電子工程研究所 === 103 === In this thesis, silver nanowires (NWs) self-assembled to Ag nanonet via ethylene glycol (EG)-assisted route is studied. Two different approaches in adding EG solution to assist Ag NWs self-assembling to form Ag nanonet were conducted. The possible mechanism and theory of Ag nanonet self-assembling are discussed. The self-assembled Ag nanonet was annealed to form fused junctions in those overlap area between Ag NWs using quartz tube furnace. Thermal budget of this annealing to form fused junctions in Ag nanonet is studied. Sheet resistance and degree of AZO film’s transparency with or without Ag nanonet embedded are evaluated.
The first part of results indicate that spray EG solution and then drip Ag NW solution on a substrate do help the self-assembling. When Ag NW solution drip onto the substrate with EG drops, it will slightly mix with EG drops. When the substrate temperature slowly increases to 40°C, the ethanol solvent evaporates first. This evaporation helps Ag NWs move slightly, the movement stops at the edges of the EG drops. (Note: EG does not evaporate easily at 40°C.) At the moment when the entire edges of EG drops surrounded by Ag NWs, the self-assembled Ag nanonet can be formed. In addition, if the EG drops contains poly(vinylpyrrolidone) (PVP), it is more effective to help the self-assembling.
At 320°C, the annealing time required to fuse Ag NWs depends on the density of the Ag NWs in the nanonet and also depends on the method used for self-assembling. The time needed for fusing NWs is 10 min if drip Ag NW solution directly on the substrate. It takes 11 min to fuse together if the substrate was pre-sprayed with EG drops, and takes 31 min to fuse if the pre-sprayed EG drops contain small amount of PVP. The sheet resistance of the AZO film with fused Ag nanonet embedded has much lower sheet resistance than that without. In one particular case, an AZO film with fused Ag nanonet embedded exhibits transmittance of 58.15% and sheet resistance of 41.27 Ω/sq. The AZO sheet resistance with fused Ag nanonet embedded is about only 2.53% of that without one. The fused NW of the nanonet has a larger diameter than the original NW and results in lower transmittance.
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