MATERIALS SCIENCE ENGINEERING
University of California at Berkeley
Fall 2013 Seminar Series
Thursday, October 24, 2013
4 – 5 pm
348 Hearst Memorial Mining Building
Dr. A. Alec Talin
Center for Nanoscale Science and Technology Adjunct Fellow
in the Energy Research Group and
A Principal Member of the Technical Staff at Sandia National Laboratories, Livermore, California
Metal-Insultor-Semiconductor Tunnel Diodes for Efficient Solar Hydrogen Production
Photoelectrochemical (PEC) water splitting represents a promising route for renewable production of hydrogen, but trade-offs between photoelectrode stability and efficiency have greatly limited the performance of PEC devices. Metal-insulator-semiconductor (MIS) photoelectrode architecture consisting of metallic “collectors” situated on the surface of a thin insulator-covered semiconductor represents an alternative approach. When the MIS photoelectrode is illuminated, minority carriers tunnel through the insulating layer to the collector, where the hydrogen (cathode) or oxygen (anode) evolution can take place. An advantage of the MIS design is that semiconductor stability and light-harvesting efficiency are decoupled, enabling narrow band gap semiconductors that are well-suited for absorbing sunlight to be used without being corroded by the electrolyte. In my talk I will describe how substantial improvement in the performance of Si-based MIS photoelectrodes can be realized through a combination of high-quality thermal SiO2 layer and the use of bilayer metal catalysts to tune the metal-semiconductor Schottky barrier [1]. If time permits, I will briefly describe other ongoing projects in my group related to energy conversion and storage.
[1] D. V. Esposito, I. Levin, T. P. Moffat, and A. A Talin, Nature Mater., 12, 562-568 (2013)
Bio: Alec Talin is a principal member of technical staff at Sandia National Laboratories, in Livermore, CA, a visiting fellow at the Center for Nanoscale Science and Technology at NIST, Gaithersburg, MD, and an adjunct associate professor of Materials Science and Engineering at the University of Maryland, College Park. He received a B.A. in Chemistry from the University of California at San Diego in 1989 and a Ph.D. in Materials Science and Engineering from the University of California at Los Angeles in 1995. Prior to joining Sandia in 2002, Alec spent six years as a research scientist at the Motorola Corporate Labs in Phoenix, AZ. Alec’s interests include novel electronic materials and devices, charge transport at contacts and interfaces, and electrochemical energy conversion and storage.
Hosted by Professor Jie Yao