Nanoscale Electrochemistry - A Tool For Forming Structures Of Almost Atomic Dimensions

June 30, 1998

The deposition of nanometer-sized clusters and the local etching of a metal surface have been achieved by applying ultrashort voltage pulses in an electrochemical scanning tunneling microscope at the Fritz Haber Institute of the Max Planck Society, Berlin (Physical Review Letters 80, 5599 (1998)).

Nanoscale Electrochemistry - a tool for the formation of structures of almost atomic dimensions. Nanostructuring of materials, i.e., its modification on a nanometer scale, is nowadays one of the key technologies for the fabrication of electronic as well as micromechanical devices. Combining this with electrochemical methods would provide a very convenient way of producing nanostructures.

Structures of different materials could be formed just by supplying these as ions dissolved in a liquid solution, i.e., an electrolyte. As published in the June 22 issue of Physical Review Letters, a group of scientists at the Fritz Haber Institute, Berlin, achieved the direct electrochemical deposition of nanometer clusters as well as the local etching of a substrate.

The authors employed an electrochemical scanning tunneling microscope (STM), where the needle-like probe of the STM and a gold sample are immersed into the electrolyte. Upon application of ultrashort voltage pulses between the STM tip and the gold surface, copper clusters containing only a couple of hundred atoms were formed on a gold surface. Similar to the processes occurring in a battery, electrons are transferred from the gold surface onto positively charged copper ions dissolved in the electrolyte. These neutralized metal atoms then stick to the surface forming a small pile of material. By reversing the polarity of the voltage pulses, the substrate itself was etched. Gold atoms lose electrons (they are oxidized), resulting in their dissolution in the electrolyte. This leads to the formation of holes on the surface, again of only nanometer dimension.

Such electrochemical modifications on the nanometer scale are in contrast to the expectations in conventional electrochemistry. There, the modifications usually occur over the entire electrodes mostly independent of the geometrical arrangement and the shape of the electrodes. Therefore, the size of modifications in conventional electrochemistry is limited to the micrometer rather than to the nanometer scale, even with very tiny electrodes.

The clue of the investigations described above is the application of very short voltage pulses (of the order of nanoseconds) and the use of a highly concentrated electrolyte. This conducts the chemical reaction far from thermodynamic equilibrium and, hence, confines it to the region around the very end of the needle-like probe. Besides the structuring of gold surfaces this method opens new avenues also for the modification and micromachining of semiconductors, the main material for modern eletronic devices. Even clusters of different materials could be deposited with this 'pulse electrochemical STM' simply by exchanging the electrolyte. This is one of the prerequisites for building a real electronic device.



Related Electrolyte Articles from Brightsurf:

Anions matter
Metal-ion hybrid capacitors combine the properties of capacitors and batteries.

AI technology can predict vanadium flow battery performance and cost
A research team led by Prof. LI Xianfeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences proposed a machine learning-based strategy to predict and optimize the performance and cost of vanadium flow batteries (VFBs).

Scientists identify solid electrolyte materials that boost lithium-ion battery performance
The discovery could help battery researchers design the first solid electrolytes that are safe, cheap and efficient.

New understanding of electrolyte additives will improve dye-sensitised solar cells
Dye-sensitised solar cells could perform better thanks to improved understanding of additives in optimising electrolytes.

Manganese single-atom catalyst boosts performance of electrochemical CO2 Reduction
A research team led by Prof. ZHANG Suojiang from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences prepared a manganese (Mn) single-atom catalyst (SAC) with Mn-N3 site supported by graphitic C3N4, which exhibited efficient performance of CO2 electroreduction.

Scientists develop low-temperature resisting aqueous zinc-based batteries
A research group led by Prof. LI Xianfeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a low-temperature resisting, cost-effective, safe and eco-friendly hybrid electrolyte for aqueous zinc-based batteries.

New battery electrolyte developed at Stanford may boost the performance of electric vehicles
Stanford researchers have designed a new electrolyte for lithium metal batteries that could increase the driving range of electric cars.

Simple is best? Simple and universal design for fuel cell electrolyte
Researchers at Japan Advanced Institute of Science and Technology (JAIST) and Dalian Institute of Chemical Physics, Chinese Academy of Sciences have successfully established a universal synthetic design using porous organic polymers (POPs) for fuel cell electrolyte, according to an Editor's choice hot article published in the journal Materials Chemistry Frontiers.

Researchers make next-generation, high-toughness battery component
By combining a ceramic material with graphene, Brown University engineers have made what they say is the toughest solid electrolyte built to date.

Lightning in a (nano)bottle: new supercapacitor opens door to better wearable electronics
Researchers from Skoltech, Aalto University and Massachusetts Institute of Technology have designed a high-performance, low-cost, environmentally friendly, and stretchable supercapacitor that can potentially be used in wearable electronics

Read More: Electrolyte News and Electrolyte Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to