Electrically tunable pore morphology in nanoporous gold thin films

作     者：Tatiana S. Dorofeeva Erkin Seker 

作者机构：Department of Electrical and Computer Engineering University of California-Davis Davis CA 95616 USA 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2015年第8卷第7期

页      面：2188-2198页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：support from UC Lab Fees Research Program Award Research Investments in the Sciences & Engineering (RISE) Award, and UC Davis College of Engineering start-up funds 

主　　题：nanoporous gold,tunable morphology,Joule heating,material screening 

摘      要：Nanoporous gold （np-Au） is an emerging nanostructured material that exhibits many desirable properties, including high electrical and thermal conductivity, high surface area-to-volume ratio, tunable pore morphology well-established surface-binding chemistry, and compatibility with microfabrication. These features make np-Au a popular material for use in fuel cells, optical and electrical biosensors, drug delivery vehicles, neural electrode coatings, and as a model system for nanoscale mechanics. In each of its many applications, np-Au morphology plays an essential role in the overall device operation. Therefore, precise morphological control is necessary to attain optimal device performance. Traditionally thermal treatment by furnaces and hot plates is used to obtain np-Au with self-similar but coarser morphologies. However, this approach lacks the ability to create different morphologies on a single substrate and requires high temperatures （〉 250 ℃） incompatible with most plastic substrates. Herein, we report electro-annealing as a novel method that permits control of the extent and location of pore coarsening on a single substrate in one fast treatment step. The electro-annealing entails much lower temperatures （〈 150 ℃） than traditional thermal treatment, putatively due to electrically assisted phenomena contributing to the thermally activated surface diffusion of gold atoms, responsible for coarsening. Overall, this approach is easily scaled to display multiple pore morphologies on a single chip, therefore enabling high-throughput screening of optimal nanostructures for specific applications.