Instrument Development for Ultrahigh-throughput 3D Chemical Imaging via Glow Discharge Optical Emission Spectroscopy

Texas Tech University, Lubbock TX

Investigators

Abstract

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Gamez at Texas Tech University is developing an ultra-high throughput surface elemental mapping technique based on measuring the light emitted from a glow discharge. It is important to obtain spatial-resolution of chemical information to order to understand natural systems and improve the efficiency of manufacturing (that is to see where impurities might be). Current imaging techniques, however, present several challenges. On the one hand, many techniques require several hours to tens of hours to obtain a surface element map with high resolution. On the other hand, current higher sample throughput techniques may not be widely accessible. Some high throughput techniques require the use of synchrotron radiation facilities which are relatively rare. Professor Gamez is working on a glow discharge optical spectroscopic technique that could potentially map element distribution >1000x faster than typical techniques. As such, imaging protocols currently limited by analysis time restrictions may become routine diagnostic tools. This research impacts many scientific research fields, from materials to biological sciences. The project also offers training opportunities to graduate and undergraduate researchers with regard to instrument development, fundamental studies, and application development in plasma-based optical hyperspectral imaging and surface analysis. Professor Gamez works with a number of local programs to recruit next generation STEM students, in particular those from underrepresented minority groups. Glow discharge optical emission spectroscopy (GDOES) has been recently shown to enable spatially resolved lateral information to be obtained from within the sputtering surface area by operating the GD in pulsed-power and at higher pressures. These modes of operation become are important as it is no longer required to raster pixel-by-pixel to obtain a hyperspectral data cube with the elemental distribution information. This savings may translates into several orders of magnitude faster analysis times. The overall goal of this project is to develop an ultrahigh throughput-, 3D-, large area surface chemical imaging technique based on GDOES. The three objectives are to: 1) develop hyperspectral imaging systems and novel GD instrumentation to enable GD 3D chemical imaging, 2) study the underlying GD mechanisms through OES and laser scattering plasma diagnostics, and 3) develop applications in materials, biological and geological sciences enabled by GDOES 3D chemical imaging. In addition to the overall goals, this research may improve comprehension of GD scaling, enhance the characterization of trends in molecular OES under GD conditions, and enable of a variety of imaging protocols in different fields.