Near-IR Module for Ellipsometry

This proposal is for acquiring a near-infrared upgrade module (e.g., source/receiver units) for in situ optical spectroscopic ellipsometry. It will enable us to build state-of-the-art operando spectroscopic characterization programs studying various energy-related materials such as lithium/sodium metals, solidstate electrolytes, semiconductors, metal-oxide thin films, and organic crystals. Operando characterizations are emerging as essential tools for the advance of future energy device technology. However, many research groups rely on ex situ characterizations or post-mortem analyses. In other words, one should disassemble processed devices such as cycled batteries and dead solar cells to see what has happened. Besides, operando approaches can provide the samples’ real-time data and nondestructive characterizations. PI and Co-PI’s have recently developed in situ optical spectroscopic ellipsometry and demonstrated its viability for operando characterizations in solid-state lithium-metal battery research [1]. It provides real-time, comprehensive information in materials science, like in vivo experiments in biology. The existing instrument, which was purchased in 2012, has a limited spectral range of 210 nm – 1000 nm in wavelength. The spectral range will be significantly extended to 1690 nm with this purchase of a new module ($25,000). Since molecular vibrations or plasmonic excitations occur in near-infrared energies, we expect that this extended spectral range will allow us to explore terra incognita of energy materials physics. It will also help us compete for energy-related funding programs using our state-of-the-art operando spectroscopic characterizations.