Surface modification for improved organic electronic devices

Speaker: 
Steven L. Bernasek, Princeton University
Date & Time: 
February 28, 2008 - 12:00pm
Location: 
Chem 260
Surface modification for improved organic electronic devices
Laboratory for Surface Modification
Steven L. Bernasek, Princeton University
12:00 Noon, Chem 260

Charge injection barriers occur at interfaces in hybrid electronic devices such as organic light emitting diodes (OLEDs) and organic thin film transistors (OTFTs). Modification of the interfaces can be used to control charge transport in the device. Surface dipole manipulation is one route to control this charge injection barrier. Another is to prepare strongly attached doped layers at the interface via appropriate self-assembly routes. We describe methods of surface functionalization that allow the realization of this barrier control on indium tin oxide surfaces used in OLED devices. These routes focus on ligand exchange chemistry or phosphonate self-assembled monolayer formation followed by carrier doping, and result in considerably improved OLED performance. Similar methods are used to fashion improved thin film transistor devices on silicon substrates, and examples of this approach are discussed. Characterization of the monolayer interfaces formed, and the device performance based on them are presented.