Gold-Coated Silicon Wafers in Electrochemistry

Gold-coated surfaces play an increasingly important role in precision imaging of various biochemical phenomena. There are many unique qualities that make gold surfaces ideal for atomic-scale observations, including near-total (>99%) reflectivity in the infrared (IR) region and useful adsorption properties with bioactive implications. This has proven pivotal in various forms of IR spectroscopy, where gold-coated glass is used as a substrate for biomolecules of interest. But glass and mica are not the only substrates used for microscopy-grade gold thin films.

At Platypus Technologies, we engineer gold-coated silicon wafers that exploit the unique electrical conductivity of both the substrate and the coating to enable advanced electrochemical experimentation.

Outlining Gold-Coated Silicon Wafers

Silicon wafers typically serve as the underlying surface for microelectronic devices such as integrated chips (ICs) and hard drive devices (HDDs). This is due to their unique semiconducting properties which are inherent to silicon and determined by the presence of specific chemical dopants. By modulating these electrical properties, silicon wafers can be engineered for specific charge-carrying capabilities and can be used as electrodes for a wide range of applications, such as electrochemical impedance spectroscopy (EIS).

What is Electrochemical Impedance Spectroscopy?

EIS is one of the most sophisticated forms of electrochemical research, providing detailed insights into complex phenomena like electron transfer resistance and surface sensitivity. It is carried out by immobilising an analyte on a semiconducting surface under an applied voltage and measuring the current response. Sometimes, silicon wafers must be functionalised with a secondary interface material to enable their use in EIS. Ultra-thin gold coatings are the go-to solution for electrochemistry silicon substrates due to their exceptional planarity and useful electronic characteristics.  

Platypus Technologies gold-coated silicon wafers have been used to study a wide range of key reaction mechanisms and electrochemical phenomena using EIS. Among these is the performance of desalination membranes as a function of salt permeability of polyamide films. With angstrom-scale topographical uniformity and outstanding surface purity, it was possible to determine the differential resistance of the polyamide films by thickness and solution concentration, thus yielding greater insights into osmotic membrane desalination performance. 

Gold-Coated Silicon Wafers from Platypus Technologies

Platypus Technologies has developed a cutting-edge workflow for developing custom gold-coated silicon wafers for electrochemistry and microscopy. All our substrates are based on electron beam physical vapour deposition of high-purity gold targets, with high degrees of adhesion between gold thin films and underlying substrates promoted by an intermediary titanium adhesion layer.

If you would like to learn more about the specifications of our gold-coated silicon wafers or want to know about partnership opportunities, why not contact a member of the Platypus Technologies team today?