Organic photovoltaic devices have been a significant part of the chemistry world for a decade or more.
Such organic constructions are important both for important applications and for the understanding of the fundamental science that is involved. The focus on this set of problems arises from our understanding of climate issues, including global warming, glacial melting, unprecedented flooding, and CO2 increase in the atmosphere.
We will examine two aspects of organic photovoltaic creation and utilization. The first will be an understanding of the most common form of solar capture, the traditional organic photovoltaic devices (OPV’s). Here, we will focus on the thermodynamic issues involved in standard OPV’s – we will see that entropy is one of the important issues for improving this form of energy capture, and for guiding the molecular structure choice.
The second aspect will be an introduction to the general problem of gathering charges in non-periodic molecular structures. We will do this using some ideas from graph theory, ideas that permit the reduction of extremely complicated problems to a single number, called the Kirchhoff index. This reduction is qualitative, but extremely useful both for guiding synthesis and for deepening understanding. We will also suggest applications to specific organic-based OPV’s.