EAGER: manipulating spin dynamics in thionated perylene diimide organic semiconductors: towards organic spin caloritronic devices

University Of Utah, Salt Lake City UT

Investigators

Abstract

Non-technical Summary Moore's Law, the dominant strategy for improving the speed and efficiency of electronic devices, relies on scaling down the transistor dimensions, so that more of them fit in a defined area, but technology is approaching a size scale in which pursuing this strategy further can only be done with an enormous increase in fabrication cost. Fundamentally new strategies are needed to accommodate society's increasing technological demands. Spin-based solid-state systems (spintronics), represent such a fundamentally new strategy. Unlike conventional electronics, where the charge of electrons is used to store and process information in transistors, spintronics uses the spin of electrons to carry digital information. With this award, which is supported by the Solid State and Materials Chemistry program in the Division of Materials Research, the principle investigator synthesizes novel n-type organic semiconductors that are good candidates for spin-based computing technologies. Due to their strong spin-dependent properties they are efficient spin-transistor materials. Additionally, the researchers investigate, if waste heat from a device may also be converted into spin currents thus increasing the overall efficiency of spin-transistor devices. An innovative education and outreach program, which includes bi-weekly hands-on research experiences related to energy conversion and storage into the science curriculum of a local urban high-need school in the Salt Lake City area, is part of this research project. Additionally, underprivileged students from local high-schools are given the opportunity to pursue research over the summer in the principle investigator's labs. Technical Summary Recent advances in the field of organic electronics have demonstrated that the physical and chemical properties of organic semiconductors can be vastly improved by tuning the molecular arrangement of the sp2 hybridized backbone system or by oxidatively doping the organic molecule to form either a p-type or n-type semiconductor. Although p-type organic semiconductors have been largely explored as potential thermoelectric and spintronic materials, n-type organic semiconductors have fallen behind due to their low electron affinities. As part of this award, which is supported by the Solid State and Materials Chemistry program in the Division of Materials Research, the principle investigator synthesizes novel n-type organic semiconductors based on the thionation of perylene diimides. Additionally, fundamental mechanistic understanding of the influence of electronic structure, morphology, intrinsic and extrinsic doping, and spins on the thermoelectric and spintronic properties of these perylene diimide n-type organic semiconductors is being elucidated. The studies investigate new breakthroughs in both materials design and modulation of fundamental physical phenomena by carefully elucidating the role of spin-orbit coupling, electron-phonon coupling, and solid-state crystal chemistry on the performance of thionated perylene diimide thermoelectric and spintronic materials. An innovative education and outreach program, which includes bi-weekly hands-on research experiences related to energy conversion and storage into the science curriculum of a local urban high-need school in the Salt Lake City area, is part of this research project. Additionally, underprivileged students from local high schools are given the opportunity to pursue research over the summer in the principle investigator's labs. 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.