Controlled Deposition of Nano-scale Dots by Electrochemical Processes

一些不寻常的物理特性将从纳米级微点——量子点——制成的材料中表现出来，在量子点中，电子的运动被限制在一个非常小的区域内。使用这种新材料，将有望开发出具有革命性优异功能的新型电子设备。在本研究中，研究者的目标是通过湿法工艺，特别是电化学工艺，如化学沉积和位移沉积，来实现纳米尺度的微点。研究人员发现，化学沉积的初始沉积适合于纳米尺寸的点。采用化学沉积法制备了镍纳米点。点的密度受催化循环次数和溶液的pH值控制。采用新开发的QCM技术对沉积过程进行监控，实现了沉积控制。采用位移沉积的方法制备了钌和钯纳米点。钌和钯离子在水溶液中很容易被锡（II）离子氧化成锡（IV）离子所提供的电子还原。该工艺可获得30 ~ 70%的钌覆盖率。从上面的结果来看，研究者成功地制造了几种纳米尺寸的点。

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.