William Mong Distinguished Lecture
by Professor Zhifeng Ren
Apr 7, 2016
Prof. Zhifeng Ren, M. D. Anderson Chair Professor, Physics Department, University of Houston, gave a lecture on April 7, 2016, titled "High Performance Thermoelectric Materials and Superflexible Transparent Conductors".
The past decade has witnessed significant advances in the field of thermoelectric materials thanks to extensive research along new pathways to enhance properties, in particular nanostructuring bulk materials to largely reduce the thermal conductivity which has resulted in peak thermoelectric figure of merit (ZT). Achieving high peak ZT has been the goal of the thermoelectric community. Is high peak ZT good enough? Does a high peak ZT necessary translated into a high efficiency? Prof. Ren answered by demonstrating how a high peak ZT cannot warrantee a high efficiency, but engineering (ZT)eng is the right answer. He also demonstrated how a high conversion efficiency does not warrantee high output power density, but the high engineering power factor (PF)eng does, and this is what matters most for thermoelectric power generators.
In the second part, Prof. Ren showed his team’s recent work on superflexible transparent conductors without fatigue. These conductors can be as conducting and transparent as ITO and stretched to 300% the original length and cycled for more than 100,000 times under stretch of 100% without fatigue.