Old Method, New Results: Ultra-High Mobility in a Simple Organic Crystalline Semiconductor – Brett Ellman

Date: Mon. October 11th, 2004, 12:30 pm-1:30 pm
Location: Rockefeller 221

Devices based on organic semiconductors are a new, growing sector of the electronics market. For use as, e.g., field-effect transistors, a primary determinant of the utility of a material is the mobility, the proportionality coefficient between charge velocity and electric field. We report detailed pulsed-laser time-of-flight measurements on a simple crystalline system, 1,4-diiodobenzene, with a room temperature mobility at least an order of magnitude larger than competing inorganic materials (e.g., amorphous silicon). I will discuss purification, crystal growth, and a detailed analysis we have developed to extract other properties besides mobilities from the time-of-flight data. Finally, I will mention ab-initio calculations of electronic structure that indicate that the iodine constituents possibly play a major role in transport.