Events
Molecular and Hybrid Solution Processable Thermoelectrics
February 15, 2011 at 3pm/36-428
Rachel Segalman
University of California, Berkeley
abstract:
Thermoelectric materials for energy generation have several advantages over conventional power cycles including lack of moving parts, silent operation, miniaturizability, and CO2 free conversion of heat to electricity. Excellent thermoelectric efficiency requires a combination of high thermopower (S, V/K), high electrical conductivity (σ, S/cm), and low thermal conductivity (κ, W/mK). To date the best materials available have been inorganic compounds with relatively low earth abundance and highly complex, vacuum processing routes (and hence greater expense), such as Bi2Te3. Molecular materials and hybrid organic-inorganics bring the promise of inexpensive, solution processible, mechanically durable devices. While highly conductive polymers are now common place, they generally demonstrate low thermopower. Our work on molecular scale junctions that nanostructuring of organics allows them to act as thermionic filters between inorganic junctions which can lead to enhanced thermoelectric properties. We have taken inspiration from this fundamental understanding to design material systems in which we combine a high electrical conductivity, low thermal conductivity polymer with a nanoparticle that contributes high thermopower. Additionally, the work functions of the two materials are well-aligned which introduces the possibility of thermionic filtering at the interface and an additional boost to the power factor. The combination of these effects results in a new hybrid, solution processible material with a thermoelectric figure of merit within an order of magnitude of the Bi2Te3. In this talk, I will discuss both the use of thermoelectric measurements to gain insight to molecular junctions and how this insight translates to design principles for polymer and hybrid thermoelectrics.
bio:
Rachel A. Segalman is an Associate Professor of Chemical Engineering at the University of California, Berkeley and an Associate Faculty Scientist in the Materials Science Division of Lawrence Berkeley National Laboratories. Segalman received her B.S. in Chemical Engineering with highest honors from the University of Texas at Austin. She then performed her doctoral work in Chemical Engineering (polymer physics) at the University of California, Santa Barbara. Following her PhD, Segalman was a postdoctoral fellow at the Universite Louis Pasteur in Strasbourg France. She then joined the faculty of UC Berkeley in the spring of 2004 as the Charles Wilke Assistant Professor of Chemical Engineering. Segalman is the author of more than 50 refereed publications including 3 invited reviews and one book chapter. She has been also been granted three patents in the field of energy research. She is an Alfred P. Sloan Fellow, a Camille Dreyfus Teacher Scholar, and has received the Presidential Early Career Award for Science and Engineering (PECASE), MDV Innovators Award, TR35: Technology Review’s Top Innovators Under 35, Hellman Family Young Faculty Award, 3M Untenured Faculty Award, NSF CAREER Award, Intel Young Faculty Seed Award, and Chateaubriand Postdoctoral Fellowship. She is currently serving on the Science and Technology Committee of the Board of Governors for Los Alamos and Livermore National Laboratory LLC and is an Associate Editor for the Annual Reviews of Chemical Engineering and is on the Editorial Board of Macromolecules. Segalman is also an active member of APS, ACS, MRS, and AIChE and is a Member at Large for the Forum on Industrial and Applied Physics (FIAP) of the American Physical Society.
