Connecting Metals and Semimetals to Semiconductors: The Ubiquity of Schottky Barriers

Tuesday, April 16, 2013 – 3:00pm
Regents 109
Art Hebard
University of Florida

It is widely recognized that interfaces between metals and most semiconductors form Schottky barriers with rectifying properties and are essential components of our modern day electronics. This talk will begin with a tutorial overview of Schottky barriers and describe the physical concepts that are necessary and sufficient to gain a working understanding of their operation. Research will then be described which uncovers surprising phenomenology that points to new physics and novel device concepts. These phenomena include a heretofore unnoted magnetodielectric coupling in nonmagnetic Au/GaAs:Si Schottky barriers, the formation of Schottky barriers at the interface of one-atom-thick zero-gap semiconductors (graphene) and conventional semiconductors, facile chemical and electric-field tuning of the Schottky barrier height of such semimetal/semiconductor diodes, and the demonstration of polymer-coated graphene/n-Si Schottky solar cells with record-high (for graphene) power conversion efficiencies approaching 9%. Graphene/semiconductor Schottky barriers not only address interesting new science but also show promise for technical applications, a promise related to graphene’s mechanical stability, its resistance to diffusion, its robustness at high temperatures, its susceptibility to be doped either by chemistry or by electric fields, and its demonstrated capability to embrace multiple functionalities.

Host: Paola Barbara
Discussion Leader: Paola Barbara