1. Neslihan Yamur 25.01.2013 Nanocomposites for Energy Application 1

2. INTRODUCTION 2 3. What is Nanocomposite ? 3 Composite materials made from two or more constituent materials with significantly different physical or chemical properties, that when combined, produce a material with characteristics different from the individual components. If the size of at least one of the component constituent is nanometric then the composite is nanocomposite. http://www.rsc.org/Publishing/Journals/cp/article. asp 4. 4 Nanocomposites for Solar Energy Storage 5. Nanocomposites for Solar Energy Storage Electron donor and electron acceptor materials is used rather than semiconductor p-n junctions. Blending the donor and acceptor phases together to obtain a nanocomposite material. 5 6. PCBM: [6,6]phenyl-C61-butyric acid methyl ester, acceptor P3HT: Poly(3-hexylthiophene), donor Electron Acceptor and Donor PCBM P3HT P3HT PCBMITO Al 3.7 eV 5.1 eV LUMO HOMO 7. Electron Acceptor and Donor P3HT PCBMITO Al 3.7 eV 5.1 eV Light Photon absorption, excitons are created Excitons diffusion to an interface 8. Electron Acceptor and Donor P3HT PCBMITO Al 3.7 eV 5.1 eV Charge separation due to electric fields at the interface. Separated charges travel to the electrodes. 9. Nanocomposites for Solar Energy Storage 9 There are two ways for fabricating devices. 1. Organic donor- Inorganic acceptor 2. Organic donor Organic acceptor 10. 10 Organic donor- Inorganic acceptor 11. First Type 11 The first structure is the inorganicorganic. A nanoporous metal oxide substrate is used as an acceptor. Polymeric material is used as a donor. 12. Inorganic Materials as Acceptor 12 1) Carbon Nanotubes 2) ZnO Nanorod or Nanowires 3) TiO2 Nanorods or Nanowires 13. Carbon Nanotubes 13 Nanotubes are cylindrical fullerenes. These tubes of carbon are usually only a few nanometres wide, but they can range from less than a micrometer to several millimeters in length. http://en.wikipedia.org/wiki/Fullerene#Carbon_nanotubes 14. Advantages of Inorganic Materials 14 To improve photovoltaic efficiency To extend the photovoltaic response into the near infrared. 15. 15 Organic donor Organic acceptor 16. Second Type 16 The second type of structure is made of a polymer/polymer or nanoparticles blend, which allows easy thin film deposition and an intimate mixing of donor and acceptor. The most popular and efficient composite is the bulk heterojunction polymer/ fullerene (PCBM) material, which is based on P3HT as a donor and a soluble fullerene derivative (PCBM) as an acceptor. 17. 17 Solar Cells Based on Poly(3- butylthiophene) Nanowires 18. Solar Cells Based on Poly(3-butylthiophene) Nanowires 18 Suitable poly(3-alkylthiophene) nanowires useful in the composites of the invention include 1) poly(3-methylthiophene), 2) poly(3-ethylthiophene), 3) poly(3-propylthiophene), 4) poly(3-butylthiophene), 5) poly(3-pentylthiophene), 6) poly(3-hexylthiophene), 7) poly(3-heptylthiophene), 8) poly(3-octylthiophene), 9) poly(3-nonylthiophene), 10) poly(3-decylthiophene) nanowires. http://www.igm.uni- stuttgart.de/forschung/arbeitsgebiete/organische_elektronik 19. Solar Cells Based on Poly(3-butylthiophene) Nanowires Chemical structures of P3BT and C61-PCBM. Schematic illustration of nanowire network of P3BT/PCBM composites.19 D., Olson, Y., Ju Lee, Effect of Polymer Processing on the Performance of Poly(3-hexylthiophene)/ZnO Nanorod Photovoltaic Devices, 2007, 16640-16645 20. Highly Efficient Solar Cells Based on Poly(3- butylthiophene) Nanowires 20 TEM (a) and AFM (b) images of P3BT-nw/C61-PCBM nanocomposites. D., Olson, Y., Ju Lee, Effect of Polymer Processing on the Performance of Poly(3-hexylthiophene)/ZnO Nanorod Photovoltaic Devices, 2007, 16640-16645 21. References N., Thien-Phap, Surface & Coatings Technology, Polymer-based nanocomposites for organic optoelectronic devices, 2011, 742752 D., Olson, Y., Ju Lee, Effect of Polymer Processing on the Performance of Poly(3-hexylthiophene)/ZnO Nanorod Photovoltaic Devices, 2007, 16640-16645 N., Henry, Polymer Nanocomposite Analysis and Optimization for Renewable Energy and Materials, University of Tennessee, 2011 21 22. 22 Thank You for Your Attention