Surface Chemistry on Molecular Materials for Next Generation Organic Semiconductor Processing

Loyola University Of Chicago, Chicago IL

Investigators

Abstract

In this project, funded by the Chemical Structure, Dynamics, and Mechanisms B Program of the Division of Chemistry and the Electronic and Photonic Materials Program of the Division of Materials Research, Professor Jacob W. Ciszek of the Department of Chemistry and Biochemistry at Loyola University Chicago is creating novel chemical solutions to processing issues associated with organic semiconductors. Organic semiconductors power modern electronics, for example the organic light emitting diodes in OLED TVs and cell phone displays. This research helps these materials reach their full potential by developing surface chemistry that can addresses flaws at the interface between the semiconductors and applied metal electrodes/contacts. Research also contributes to the fundamental understanding of the surface phenomena which are the important first step in the reactions of all molecular materials. The project also continues the Emerging Scientist Workshop, which immerses high school students in actual experiments performed by the host laboratories, and provides information on a broad spectrum of scientific fields, and advice on scientific careers. Monolayers on classical solid substrates (Alumina, Silicon, Silicon oxide, etc.) were developed decades ago but have not been developed for the new molecular thin films utilized in many modern electronic devices. Accordingly, this project develops monolayers for two molecular surfaces, 2,2ʹ,2ʹʹ-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi, a benchmark OLED material) and pentacene (the organic field effect transistor benchmark) via vapor dosing of the reactants onto the solid surface. Chemical challenges include molecular orientation within the substrate which dictates reactivity and surface defect nucleation of reactivity generating non-uniform coverages. Upon successful development of reaction, molecular series are utilized to eliminate metal penetration issues for top contacts deposited onto TPBi, while reactions on pentacene are utilized to increase conductivity in devices. In the latter, the molecular series is designed to elucidate the mechanism behind increased conductance. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.