Program Highlights

Organic Molecular Layers for Efficient Charge Injection

Peter A. Dowben, Axel Enders
Nebraska MRSEC

Luis Rosa
University of Puerto Rico - Humacao

Julian Velev
University of Puerto Rico - Río Piedras

High conductivity and efficient charge injection into organic layers could lead to the design of more efficient organic solar cells and molecular electronics, especially light emitting diodes. Most organic materials are however insulators and only few exhibit high conducting properties. Nebraska MRSEC researchers in collaboration with their colleagues at University of Puerto Rico have discovered that zwitterion molecules of the p-benzoquinonemonoimine type are different from being a standard insulator. Using state of the art electron spectroscopy techniques and sophisticated first-principles calculations the researchers explored the electronic band structure of these organic molecular layers. They found a compelling evidence of the electronic pockets at the Fermi energy in these molecules thus indicating a possibility of charge injection. This discovery broadens the class of organic compounds that may be used for efficient charge injection and hence for the design of novel organic solar cells and light emitting diodes.

This research is supported by the National Science Foundation, Division of Materials Research, Materials Research Sciences and Engineering Program, Grant 0820521.