NUIM Math. Physics seminar

Joshua Schrier  
Haverford College, Pennsylvania

Sculpting the electronic states of organic and inorganic nanostructures

Friday 25 June at 2.00 p.m.

Rm 1.10, Mathematical Physics Dept, Ground floor, Science Building, North Campus.

Abstract:

Nanostructured materials offer the promise of fine-tuned properties and a wide range of applications. Two general strategies exist for tuning the properties: (1) Harnessing quantum mechanical size and shape effects, and; (2) Modifying chemical structures. The former is widely used for inorganic semiconductor nanostructures (e.g., nanocrystals, nanowires, etc.); the latter widely used for organic nanostructures (e.g., self-assembled organic materials, organic semiconductors). Both classes of materials present a formidable theoretical challenge, as the length scales of experimental interest are greater than the typical ~Smolecule~T (well described by modern ab initio quantum chemistry methods) but smaller than bulk solids (well described by solid state physics methods). Both require a balance between atomistic detail and computational efficiency, providing an opportunity for discerning the essential physical properties needed for a sufficiently accurate description. This talk will present an overview of work addressing both these areas, as well as an intermediate case that combines both approaches. I will begin by discussing work on quantitative understanding of nanowire optical and electronic properties. This will be followed by a discussion of work on computing the charge mobility of organic semiconductors. Finally, I will argue that graphene nanostructures can be best understood by combining both the "quantum confinement" and "chemical" tuning strategies. For each case, applications to solar energy utilization will be discussed.

All are welcome. Tea/coffee and biscuits to follow. For directions to the Dept. please check http://www.thphys.nuim.ie/map.php