Physical Properties of Materials: Long Range Coherent Spin Transport in Disordered Organic Solids
Abstract
Spatial spin control and the ability to transport spin information over a large distance is critical for applications in spintronics that heretofore have been limited due to lack of appropriate materials systems. Under the proposed program, we will investigate novel photophysical and magnetic properties that arise due to energetic interactions in organics and across organic/inorganic heterointerfaces based on spin transfer and transport under external or internal magnetic fields. We will exploit zero field splitting that lifts the degeneracy between the triplet states in organic molecules to preserve spin orientation over long distances at room temperature. Thereby, we will reveal the governing physics of spin transport in organic thin films and its dependence on film morphologies, from single crystal to polycrystalline to amorphous. Further interfacing with inorganic semiconductors, we will demonstrate controlled spin injection across a hybrid organic/inorganic heterointerface and spin transport of hybrid excitons both parallel and perpendicular to the heterointerface. Such hybrid interfaces provide opportunities to manipulate spins over long (~ microns) distances, as well as to selectively prepare stable spin states in organics prior to injection into an inorganic semi-conductor for use in a spin selective (i.e. spintronic) device. Thus, we will introduce a new hybrid spintronics material platform that merges advantageous physical properties of both organics and inorganics. To manage spin transport, we will develop a novel, nanoscale, planar ÒStern-GerlachÓ structure that can separate and transport selected spin states over distances of hundreds of nanometer. The on-chip spin orientation and transport manipulation tools will serve as unique test beds to evaluate both the spin properties of materials as well as other near-field phenomenon such as heat and light energy transfer. The transport will be studied using the unique diffusion microscope, ultrafast spectroscopy techniques, and k-space microscopy aided with electrical characterization available in our laboratories. The proposed work encompasses design and experimental components, and addresses the fundamental aspects of the magnetic properties of hybrid heterointerfaces. The knowledge developed under the proposed work is poised to open a plethora of as-yet unimagined applications ranging from quantum information processing, ultrahigh sensitivity photodetection and solar energy generation, biochemical sensing to beyond-CMOS devices. Furthermore, the objectives are aligned to Army Research OfficeÕs interest in understanding fundamental physical properties of materials that could lead to the discovery of the unexpected as well as the unknown.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 25, 2021
- Source ID
- W911NF2110116
Entities
People
- Stephen R. Forrest
Organizations
- Army Contracting Command
- United States Army
- University of Michigan