Mikis M. Mays Jr.

Advisor: Prof. Rosario Gerhardt

will propose a doctoral thesis entitled,

Influence of Controlled Film Fabrication and Thermal Processing on the Structure-Property Relationships of Sol-Gel Processed Indium Tin Oxide Thin Films

On

Tuesday, May 19 at 2:30 p.m.

Love Room 184

Abstract

Indium Tin Oxide (ITO),  a material that is both transparent and conductive, is used in optoelectronic devices such as photovoltaics and LEDs. Sputtering, a commercial thin film deposition technique, wastes indium resources by coating the entire chamber with ITO. Although sputtering is often used to fabricate highly conductive samples, alternative methods of thin film fabrication are needed for reducing indium consumption. Sol-gel based deposition methods, such as spin-coating, dip-coating, and inkjet printing waste less indium, but often suffer from high resistance, preventing their use in commercial applications that require high conductivity. The first part of this work will evaluate how the correlation between laboratory fabrication conditions affects resultant sample morphology and conductivity. This synergistic behavior will be measured using impedance spectroscopy, UV-Vis spectrophotometry, and various microscopy methods. Furthermore, alternative annealing methods such as rapid thermal annealing and flash lamp annealing are explored to determine the combined effect of various thermal treatment techniques and optimized sol-gel processing such that a reproducible method for obtaining reproducible and conductive transparent sol-gel ITO thin films are obtained. The second phase of this research will investigate the relationship between thermal processing and the nucleation and growth of ITO sol-gel thin films using multimodal characterization techniques such as neutron reflectivity, x-ray characterization, ToF-SIMS and STEM analysis. This will allow us to form a connection between the film’s structure, elemental distribution, and its final properties. As a result, the proposed research will provide insight into how to decrease resistivity within sol-gel processed thin films, understanding the phase transformation behavior of sol-gel systems, optimizing the sol-gel thin film fabrication process, tuning film properties, and decreasing overhead costs for ITO deposition. Finally, the insights obtained in this research will be used to fabricate high-performance sol-gel processed ITO thin films suitable for optoelectronic applications. The utility of the optimized sol-gel-process will then be assessed by using sol-gel derived ITO films in devices and composite materials.

Committee

• Prof. Rosario Gerhardt – School of Materials Science and Engineering (advisor)
• Prof. Mark Losego – School of Materials Science and Engineering
• Prof. Faisal Alamgir – School of Materials Science and Engineering
• Prof. Yong Ding – School of Materials Science and Engineering, Institute for Matter and Systems
• Dr. Jim Browning – Neutron Reflectometry Group Leader, ORNL