| Flat panel displays have become ubiquitous in many applications, including desktop panels, laptops, and cellular phones. The display industry is moving towards plastic displays to open up new applications where lightweight, robustness, and flexibility are of the utmost importance. Transparent conducting films on glass substrates have provided the display industry with the ability to electronically control images and information for years. Transparent conducting substrates are an essential component to electronic display technologies as they provide the contact electrodes used to address the electrooptic medium. The most common transparent conducting film for this application has been indium-tin-oxides on glass substrates because of its high conductivity (low sheet resistance) and high transmission (80%), two essential parameters for an efficient display.; To meet the requirements and technological demands needed to achieve a robust, lightweight and low-power display device, plastic substrates are considered. Transforming the glass substrate to plastic provides a solution to heavy, power-hungry displays, but also presents some additional challenges. This dissertation focuses on electromechanics research performed on indium-tin-oxide (ITO) coated polyethylene-terephthalate (PET) plastic substrates to analyze the electromechanical properties of these layers. In addition to ITO/PET, this thesis moves into the evaluation of modern materials contending to replace ITO in the future, such as conducting polymers and carbon nanotube technology.; The electrical, mechanical and optical properties of transparent conducting substrates are characterized and analyzed using two main characterization methods: uniaxial tension testing and fatigue cycling. The electrical property, primarily the surface resistance, of three conducting substrates is defined. The three substrates include indium tin oxide, carbon nanotubes and organic poly(3,4-ethylenedioxythiophene) (PEDOT):poly(styrene sulfonate) (PSS) layers on polyethylene-terephthalate (PEDOT:PSS). The surface resistance as a function of mechanical deformation for the films is monitored in-situ to define the correlation between electrical and mechanical properties.; The electromechanical behavior of transparent conducting substrates will provide vital information to flexible displays and flexible device applications currently under development. This work will also help to better understand the lifetime reliability mechanisms associated with devices fabricated on flexible substrates. |
