Title: Light effect transistors (LETs) for high speed and low energy computing
Speaker: Yong Zhang（Bissell Distinguished Professor, Electrical and Computer Engineering Department, University of North Carolina at Charlotte, USA）
Time: Apr. 22, 2016 14:00PM
Venue: No. 101 Meeting Room of the library, IOS, CAS
Abstract: The LET concept explores a well-known phenomenon, photoconductivity, for computing-related, logic applications, intending to enable the continuation of Moore’s law beyond FETbased technologies [1,2]. As the term implied, photoconductivity has naturally been used for photo-detection applications. Despite the fact that metal-semiconductor-metal (M-S-M) photo-detectors, with a frequency response up to 500 GHz or a sub-ps response time, have been reported for more than two decades, these detectors are not automatically suitable for the computing application, because the switching energy could be too high or has not been explicitly evaluated. Our recent proposal on the LET concept is based on the first characterization of M-S-M detectors using the performance metrics appropriate for computing applications. Besides replicating the basic functions of a FET, a LET offers key advantages over a FET in three aspects: (1) simplicity in device structure (cost reduction), (2) higher performance potential, and (3) low energy operation. It further offers unique capabilities not typically available in a FET, such as multiple independent gating for optical logic operation and optical amplification for analog applications. These functionalities have been experimentally demonstrated using micron scale devices that can already offer comparable performance to modern FETs.
[1] J. Marmon et al., Light-Effect Transistor (LET) with Multiple Independent Gating Controls for Optical Logic Gates and Optical Amplification, Front. Phys., 21 March 2016.
[2] The Nanodevice Aiming to Replace the Field Effect Transistor,MIT Technology Review
Biography：Yong Zhang received B.S. and M.S. in Physics from Xiamen University, and Ph.D. in Physics from Dartmouth College. He is Bissell Distinguished Professor with ECE Dept of UNC-Charlotte since 2009, and adjunct Professor of Physics Dept..Prior to that, he was Senior Scientist with National Renewable Energy Laboratory (NREL). Other positions he has held include “Chairesd'excellence” ofNanosciences Foundation (France) 2010 – 2012; Academic Committee member, State Key Laboratory of Photovoltaic Science and Technology (China); Guest Professor, Institute of Semiconductors, CAS; CAS Oversee Review Committee Members. His current research activities include semiconductor nanostructures and devices, type II semiconductor superlattices, inorganic-organic hybrid materials, 2D materials, solid state lighting materials and devices, and fundamental sciences in solid state physics. He has published more than 200 papers and book chapters. He can be contacted at yong.zhang@uncc.edu.