Dissolution dynamics of thin films measured by optical reflectance

Area of Science:

• Materials Science
• Electrochemistry
• Surface Science

Background:

• In situ measurement of thin film dissolution dynamics with high spatial and temporal resolution is challenging.
• Existing methods like scanning electrochemical microscopy are slow due to specimen scanning.

Purpose of the Study:

• To develop a simpler, faster in situ characterization technique for measuring thin film dissolution rates.
• To demonstrate the technique's capability in analyzing electrochemical dissolution of copper thin films.

Main Methods:

• Utilized a setup comprising an optical microscope, a digital charge-coupled device camera, and a computer for image processing.
• Employed optical imaging to monitor the dissolution process of thin films over time.

Main Results:

• Achieved detection of dissolution rates on the order of nanometers per minute.
• Demonstrated the technique's effectiveness by analyzing the electrochemical dissolution of copper thin films on gold substrates in hydrochloric acid.

Conclusions:

• The developed optical microscopy technique offers a simple and effective method for in situ dissolution rate measurements.
• The technique's resolution is limited by the imaging and recording setup.
• Applicable to various systems, including thin film sensors and passive coatings, due to its laboratory implementability.