Research Mission: Fundamental Physics in the Organic and Carbon Electronics Lab
Organic Electronics has reached a stage of significant consumer electronics impact (OLED displays) and steadily increasing promise for photovoltaic technology. This current status has been the result of many decades of translating hard-won knowledge about the fundamental physical properties of conjugated carbon-based materials into optoelectronic applications.
Figure 1. Schematic work flow leading to progress in application of organic semiconductor materials to optoelectronic devices. Pictures on the right from wikipedia articles about OLED's and OPV's.
Our group is motivated to run the flow chart in Figure 1 almost in the opposite direction. We think the organic optoelectronic materials class can generate new insights into fundamental problems in condensed matter physics that we regard as a worthy end-goal. In particular, the structural and electronic complexity of organic semiconductors and polymer films provides an interesting framework for addressing the impact disorder in condensed matter.
For example, the prominence of structural and electronic disorder in organic electronic materials drives a tendency toward carrier localization. This is an important fundamental topic dating back to to the prediction of Anderson Localization [1] of non-interacting electronic systems. It has recently been realized that even systems with strong interactions are susceptible to disorder-induced localization termed "Many Body Localization" (MBL) [2]. This really broadens the scope of physical circumstances where carrier localization is a dominant paradigm. Importantly, MBL systems cannot be viewed as "thermalized" in the usual statistical mechanics sense and so applying equilibrium or near-equilibrium thermodynamics to their behavior is not justified.
[1] P.W. Anderson Phys. Rev. 109, 1492 (1958).
[2] Nandkishore and Huse, Annu. Rev. of Cond. Matt. Phys. 6, 15 (2015).
Selected Research Highlights (click to read more):
Controlling Interfacial Spin Filters using Alq3 and Related Molecules
Magnetoelectric Oxide Gates for Graphene Spin Transistors
Unusual Surface Terminations in Topological Insulator Crystals
Sliding Defects in Planar Aromatic Films
Spin Crossover for Molecular Spintronics
Oxide Growth on Graphene by Pulsed Laser Deposition
Sodium Intercalation of Epitaxial Graphene
General Research Overview (ca. 2015) (click to enlarge):
