Controlled Deposition of Nano-scale Dots by Electrochemical Processes

由纳米微点、量子点组成的材料将产生一些不寻常的物理性质，其中电子的运动被限制在非常小的区域内。通过使用这种新材料，具有革命性优异功能的新电子设备将是可望的。在这项研究中，研究人员的目标是通过湿法工艺，特别是化学沉积和置换沉积等电化学工艺来实现纳米级微点。研究人员发现，化学沉积的初始沉积适合于纳米级的网点。采用化学沉积法制备了镍纳米点。网点的密度受催化循环次数和溶液pH的控制。利用最新发展的QCM技术对沉积过程进行监控，实现了可控沉积。采用置换沉积的方法制备了Ru和Pd纳米点。在水溶液中，Ru和Pd离子很容易被TiN(II)离子氧化成TiN(IV)离子提供的电子还原。该工艺可获得30-70%的Ru覆盖率。根据以上结果，本研究人员成功地制备了几种不同尺寸的纳米点。

Some unusual physical properties will come out from the materials made of nano-sized microdots, quantum dot, in which movement of electrons is limited in a very small area. New electronic devices that have revolutionary excellent functions will be expected by using such new materials. In this study the investigator aims to realize the nano-scaled microdots by means of wet processes, especially electrochemical processes such as electroless deposition and displacement deposition. The investigator revealed that initial deposits of electroless deposition were suitable for the nano-sized dots. Nickel nano-dots were fabricated by electroless deposition. Density of the dots was controlled by the number of catalyzation cycles and pH of solutions. The controlled deposition was realized by monitoring the deposition process with a newly developed QCM technique. Ruthenium and palladium nano-dots were also fabricated by means of displacement deposition. Ruthenium and palladium cations were easily reduced by electrons supplied from an oxidation process of tin (II) ion to tin (IV) ion in aqueous solutions. The ruthenium coverage of 30 - 70% was obtained from the process. From the results shown above, several kinds of nano-sized dots were successfully fabricated by the investigator.