Organic semiconductors comprise a scientifically and technologically important class of materials, in-tensively researched for applications in electronic and optoelectronic devices. This class of materials of-fers tunable electronic/optical properties which exhibit remarkable physical properties, and can be depos-ited as high quality thin films on a variety of substrates, including low cost glass and plastic, potentially enabling cost-effective, large-area electronics and energy conversion devices. In the course of research involving organic semiconductors, exotic molecules are engineered and synthesized, and subsequently incorporated into devices. Unfortunately, exploratory synthesis yields are often low (resulting in < 10-3 g quantities), and costs of device fabrication are high (> $105 for equipment). Moreover, the materials utili-zation efficiency of currently employed thin-film deposition techniques is often less than 0.01%, leading to a range of practical limitations on the pace of experimental exploration and increasing potential health hazards to the researchers. To address these problems, we will develop a Guardflow-enhanced Organic Vapor Jet Printing (G-OVJP) deposition system that allows compact and cost-effective deposition with much higher (50%+) source material utilization. The vapor jet technique employs a carrier gas to deliver source molecules onto a substrate, increasing materials utilization by bringing the sample into close proximity of a collimated source. The specially designed guard flow shields the stream of the source material from the surround-ings, thereby allowing the deposition to take place in a highly localized inert environment, potentially enabling device printing in atmosphere. The potential impact of the proposed work includes greatly reducing the cost-of-entry for organic op-toelectronics research, facilitating cross-disciplinary collaborations, enabling access to materials and mor-phologies not available via existing deposition techniques, and an accelerated pace of discovery in the realm of scientifically and technologically important organic semiconductors.
A relatively novel class of carefully engineered organic materials derived from pigments is becoming increasingly important in science and technology. The accelerated pace and volume of research directed towards molecular organic semiconductors is motivated in large part by the ability to span a vast range of properties by means of chemical synthesis, and by the potential ability to cost-effectively fabricate futur-istic devices (e.g. ultra-thin bendable displays, efficient lighting wallpaper, plastic solar cells, health-monitoring devices, and others). Unfortunately, present research activities are severely limited by the high costs of processing equip-ment, waste of exotic new materials due to inherent inefficiencies of the laboratory-scale processing methods employed, and the serial and slow nature of experimentation imposed by the current crop of processing equipment and methods. The proposed research apparatus - Guardflow-enhanced Organic Vapor Jet Printer - will increase ma-terials utilization efficiency by orders of magnitude, free up laboratory space, reduce capital costs, im-prove safety, speed up laboratory-scale fabrication and testing of novel devices, and enhance scientific collaborations across traditional disciplinary boundaries. The benefits of this proposed work will extend beyond the research community, to undergraduate and K-12 education, by providing greatly simplified and more rewarding hands-on experiences in science and technology at the cutting edge of research in organic semiconductors and energy conversion devices.
