Shedding some light on liquid crystalline organic semiconductors – Brett Ellman

Date: Mon. February 25th, 2013, 12:30 pm-1:30 pm
Location: Rockefeller 221

We live in a world whose technology is ruled by a small set of inorganic semiconductors, notably silicon. Research on organic semiconductors (OSCs), molecular materials based on organic compounds, seeks to supplement the reigning paradigm rather than to supplant it. In particular, OSCs may improve photovoltaics, LEDs, sensors, and flexible, cheap electronics. In this talk, I will describe recent work at Kent State on liquid crystalline (LC) semiconductors, a subclass of OSCs that offer distinct advantages and disadvantages relative to more common crystalline or polymeric organics. After a (very) short introduction to the physics of OSCs and LCs, I will discuss how the ability to align the molecules in LC OSCs over macroscopic distances can (profoundly) improve transport characteristics. I will then talk about how the surface modifications we use to align the material can drastically change the physics of photogeneration in LC OSCs. Lastly, I will offer a description of ongoing work to fabricate highly ordered heterogeneous photovoltaic devices based on phase-separated LC and polymeric OSCs.