High-resolution orthogonal patterning of organics

Organic electronics is a fast developing branch of modern science and technology that can complement conventional inorganic materials with lightweight, inexpensive, and mechanically flexible organic semiconductors. One of the key advantages of organic electronic materials lies in the low temperature, high-throughput device fabrication they enable. The solution-based fabrication of a variety of devices such as organic light emitting diodes (LEDs), field-effect transistors (FETs), solar cells, and sensors has been demonstrated using spin coating, ink-jet printing, and other wet printing techniques. While substantial improvements in materials synthesis, purification and deposition techniques over the past two decades enhanced film quality, uniformity, and environmental stability, the chemical processing of organic electronic materials remains one of the main challenges to be overcome. By chemical processing we mean any chemical treatment such as cleaning, depositing a second layer from solution to form multilayer devices, and depositing/developing resist layers for photolithographic patterning. The latter has, over the many decades of its development, grown into the dominant patterning technique in the semiconductor industry, for a number of important reasons. It offers an impressive combination of high resolution, precise registration, tight critical-dimension control, parallel throughput and the ability to cover large areas as demonstrated in the manufacture of LCD backplanes on glass sheets the size of a king bed. While cutting-edge photolithography equipment is very expensive, last generation technology is affordable and forecast to make an impact in organic electronics, especially given that alternative technologies such as inkjet printing are still largely unproven for large-scale manufacture.This project aims to leverage orthogonal lithography in order to create unique device architectures that will elucidate the fundamentals of organic electronic materials. Key research opportunities such as the ability to probe charge transport in a single crystalline domain of a conjugated polymer will be the focus of the proposed research. Orthogonal lithography, a breakthrough patterning process for organic electronic materials involves the use of resists soluble in fluorous solvents and resulted from a successful Materials World Network Project. Orthogonal lithography will be used to make complex, multilayer organic semiconductor devices not possible by other means. This will enable new fundamental studies to elucidate aspects of the physics of organic electronic devices which cannot be studies in more conventional structures.