Date of Award
Master of Science (MS)
Randall L. Headrick
Incredible achievements have been made in the field of organic electronics in small-scale laboratory settings. A topic of increasing importance is the realization of the potential for these technologies to be applied in an industrial setting. This is a deceptively challenging process, considering that many of the procedures used to attain exceptional results in a laboratory setting are not viable for translation to larger scale fabrication efforts. Moreover, upscaling fabrication is further complicated by the enormous barrier of entry due to the expensive equipment required to fabricate organic electronics at larger scale as well as the exponentially greater quantity of costly resources consumed in the fabrication process. Setting fully roll-to-roll processing as the eventual target, this project aims to develop a platform for solution processing, an important step in organic electronics fabrication, that could serve as an intermediate between small-scale techniques typically utilized in a laboratory setting and large-scale techniques found in industrial settings. The small-scale roll coater developed in this project fulfilled these aims, providing a platform to utilize previously developed solution processing technologies such as the microslot writer at a variety of speed and temperature conditions ranging from those typical in small-scale fabrication to those approaching what could be considered high throughput. Furthermore, the roll coater provides the opportunity to scale down some fabrication techniques typical of industrial fabrication settings, such as slot-die coating, such that they can be evaluated without the requisite investments of large-scale production.
In order to test the capabilities of the roll coater, it was used in the solution processing steps in the fabrication of organic field-effect transistors utilizing the organic semiconductor material C8-BTBT. These transistors, fabricated on flexible Corning® Willow® glass, were first fabricated under conditions that had already been shown to produce high performance transistor devices in small-scale experiments. Further transistor samples were fabricated with the use of much higher solution processing speeds. All the samples were characterized and compared through the calculation of their saturation mobility, threshold voltage, and yield. Comparing the mobility and yield to values attained at a smaller scale showed the potential of the roll coater as an implement in the upscaling of organic electronics fabrication techniques, but also demonstrated that there are many improvements yet to be made.
Number of Pages
Benson, Jared, "Small-scale Roll Coating as a Transitional Stage in the Scaling of Organic Electronic Device Fabrication Techniques" (2021). Graduate College Dissertations and Theses. 1389.