Breaking crystal symmetry – energy conversion with piezo/ferroelectric materials
Event details
| Date | 10.11.2014 |
| Hour | 13:15 › 14:15 |
| Speaker | Prof. Steve Dunn, Queen Mary University of London, England |
| Location | |
| Category | Conferences - Seminars |
In the last 10 years there has been growing interest in investigating the impact of non-centrosymmetry of piezo or ferroelectric materials for energy harvesting devices. The range of devices that are being investigated include those that can convert kinetic energy into electrical energy and the conversion of sunlight into fuels, known as solar fuels, or produce electrical energy such as in a photovoltaic device. The fundamental principle and area of most interest, behind these energy conversion processes are related to the breaking of crystal symmetry that is found in a piezo or ferroelectric material. This breaking of the crystal symmetry intimately influences the physical properties within the material and leads to some very specific, and analogous, behaviour. In this talk I will show how the domain structure of a ferroelectric material can effectively separate photoinduced carriers. This leads to regio-specific photochemistry where oxidation and reduction occur on predefined areas of the photocatalyst surface, separated by tens to hundreds of nanometres. I will then show how the dipole of the ferroelectric crystal lattice can be used to produce enhanced photocatalytic efficiency and how these dipoles are possibly responsible for retarding the recombination of photoinduced carriers. We have recently measured carrier lifetimes in BaTiO3 using transient absorption spectroscopy at 1-2 seconds without any external applied field. The same fundamental phenomena is responsible for the 50% increase in power conversion efficiency in a ZnO based photovoltaic device when music is played and also enables us to effectively convert vibration into an electrical output. I’ll end by drawing a picture of how the breaking of crystal symmetry may influence energy conversion in the future.
References
Acoustic enhancement of polymer/ZnO nanorod photovoltaic device performance., Shoaee S, Briscoe J, Durrant JR and Dunn S. Advanced Materials vol. 26, (2) 263-268.
Measurement techniques for piezoelectric nanogenerators., Briscoe J, Jalali N, Woolliams P, Stewart M, Weaver PM, Cain M and Dunn S. Energy and Environmental Science vol. 6, (10) 3035-3045.
Effect of ferroelectricity on solar-light-driven photocatalytic activity of BaTiO3 - Influence on the carrier separation and stern layer formation., Cui Y, Briscoe J and Dunn S. Chemistry of Materials vol. 25, (21) 4215-4223.
See what we are upto - http://www.youtube.com/watch?v=nmn3LNAiNBA
Read about what we do - New Scientist, Nov 7th
Hear what we do – Radio 4, Inside Science (we are at 10 mins)
Bio: I am part of the management team for the collaborative Doctoral Training Centre that runs with Imperial College - www3.imperial.ac.uk/plasticelectronicsdtc - which enables students to undetake a wide range of PhD projects offered by either of the host institutions.
In my spare time I enjoy cycling and previously spent a good deal of time sailing, which I did upto European level, winnning a UK National Championships in 2003 and placing top 3 in various European events. Through sailing I obtained full blues from Edinburgh and Cambridge Universities and learnt alot of valuable transferable skills, by helping support and volunteering my time at clubs and coaching other sailors. I also love being outdoors either in the garden growing as many variety of chillis as I can or climbing up a mountain.
References
Acoustic enhancement of polymer/ZnO nanorod photovoltaic device performance., Shoaee S, Briscoe J, Durrant JR and Dunn S. Advanced Materials vol. 26, (2) 263-268.
Measurement techniques for piezoelectric nanogenerators., Briscoe J, Jalali N, Woolliams P, Stewart M, Weaver PM, Cain M and Dunn S. Energy and Environmental Science vol. 6, (10) 3035-3045.
Effect of ferroelectricity on solar-light-driven photocatalytic activity of BaTiO3 - Influence on the carrier separation and stern layer formation., Cui Y, Briscoe J and Dunn S. Chemistry of Materials vol. 25, (21) 4215-4223.
See what we are upto - http://www.youtube.com/watch?v=nmn3LNAiNBA
Read about what we do - New Scientist, Nov 7th
Hear what we do – Radio 4, Inside Science (we are at 10 mins)
Bio: I am part of the management team for the collaborative Doctoral Training Centre that runs with Imperial College - www3.imperial.ac.uk/plasticelectronicsdtc - which enables students to undetake a wide range of PhD projects offered by either of the host institutions.
In my spare time I enjoy cycling and previously spent a good deal of time sailing, which I did upto European level, winnning a UK National Championships in 2003 and placing top 3 in various European events. Through sailing I obtained full blues from Edinburgh and Cambridge Universities and learnt alot of valuable transferable skills, by helping support and volunteering my time at clubs and coaching other sailors. I also love being outdoors either in the garden growing as many variety of chillis as I can or climbing up a mountain.
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- General public
- Free
Organizer
- Holger Frauenrath
Contact
- Holger Frauenrath