1 / 20

P3HT:PCBM

P3HT:PCBM. Possible way to home-use solar cell “foliage”. Ge, Weihao. Cathode. Acceptor. Donor. Anode. Sunlight. Schematic of solar cell working process. Major steps of the working process of all solar cells. Absorb photon Create charge Collect charge.

yoshe
Download Presentation

P3HT:PCBM

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. P3HT:PCBM Possible way to home-use solar cell “foliage” Ge, Weihao

  2. Cathode Acceptor Donor Anode Sunlight Schematic of solar cell working process Major steps of the working process of all solar cells Absorb photon Create charge Collect charge Efficiency - Stability - Synthesis

  3. Step1: Absorption • Factors: • Intensity at the active layer • concentrating devices • decreasing surface reflection • Band structure of the material Efficiency - Stability - Synthesis

  4. Step1: Absorption • Absorption Spectrum: • Photoelectric effect • for λ > λmax, photon passes through • for λ< λmax, Excessive energy is wasted in the form of heat. • Absorption spectrum of P3HT:PCBM blends: Cook et al. J. Phys. Chem. C, Vol. 113, No. 6, 2009 Efficiency - Stability - Synthesis

  5. Step1: Absorption • Spectrum: • Difference from inorganic solar cell materials • Band gap width: • Si: • organics: higher absorption at UV • Adjustable Chapin et al. J.Appl.Phys.25 (1954) pp. 676 Cook et al. J. Phys. Chem. C, Vol. 113, No. 6, 2009 Efficiency - Stability - Synthesis

  6. Step2: Charge generation • Exciton creation: • Electron and hole are paired via (screened) Coulomb interaction • Binding energy of excitons • A very high separation rate: which is not good. Ashcroft et al. “Solid State Physics” ISBN: 7-5062-6631-8/O•482 pp.626-628 Cook et al. J. Phys. Chem. C, Vol. 113, No. 6, 2009 Efficiency - Stability - Synthesis

  7. Step2: Charge generation • Exciton separation: • Diffusion, -> recombination / separation • Difference from inorganic ones • higher binding energy • lower diffusion range Efficiency - Stability - Synthesis

  8. Step2: Charge generation • Exciton separation: • Internal field at junctions • how is an internal field built up? • – Fermi energy must be matched when in equilibrium • Some properties of heterojunction • Window effect • superinjection • Bulk heterojunction in organic materials • Enlarge D-A interface • Excitons meet field within diffusion range Alferov, Nobel Lecture, Dec. 8, (2000) Hoppe, et, al. J.Mater.Res., Vol.19, No.7, Jul (2004) Efficiency - Stability - Synthesis

  9. Step 3: Charge Collection • Challenges: poor charge mobility • High surface resistivity • Diffused metal particles from the cathode impairs acceptor’s strength • Bulk heterojunction Hoppe, et, al. J.Mater.Res., Vol.19, No.7, Jul (2004) Christoph, et, al. Adv. Funct. Mater. 2001, 11, No. 5, October Mayer, et,al. Materials today, Vol.10, No.11, Nov. (2007) pp.28-33 Efficiency - Stability - Synthesis

  10. Methods to improve efficiency • Additional layers: • Optical spacer • Buffer layer P.D. Andersen et al., Opt. Mater. (2008), doi:10.1016/j.optmat.2008.11.014 Y.Zhao,etal.,Sol.EnergyMater.Sol.Cells(2009),doi:10.1016/j.solmat.2008.12.007 Efficiency - Stability - Synthesis

  11. Methods to improve efficiency • Morphology: • Experiment results • Enhanced absorption • Enhanced charge mobility P. Vanlaeke et al. Solar Energy Materials & Solar Cells 90 (2006) 2150–2158 F. Padinger, et al. Adv. Func. Mat. 13 (2003) 85. Efficiency - Stability - Synthesis

  12. Methods to improve efficiency • Thermal annealing • Nanocrystal of PCBM • P3HT rod-like crystalline X.Yang, et al. Nano Lett., Vol. 5, No. 4, 2005 P.Vanlaeke et al. Solar Energy Materials & Solar Cells 90 (2006) 2150–2158 Efficiency - Stability - Synthesis

  13. Methods to improve efficiency • Thermal annealing • In blends, crystallization inhibited • by annealing, resumed P.Vanlaeke et al. Solar Energy Materials & Solar Cells 90 (2006) 2150–2158 J.Zhao, et al. J. Phys. Chem. B 2009, 113, 1587–1591 Efficiency - Stability - Synthesis

  14. Methods to improve efficiency • Supplements • Dye • Enhance IR absorption • Lower exciton separation percentage E.Johansson, et.al. J. Phys. Chem. C, 2009, 113 (7), 3014-3020 Efficiency - Stability - Synthesis

  15. Methods to improve efficiency • Supplements • Hole-extraction layer, increasing surface conductivity • ITO anode • PEDOT:PSS, as modifier and as anode • Carbon nanotube J.Kang, et.al; Electrochemical and Solid-State Letters, 123 H64-H66 2009 A. Colsmann et al. Thin Solid Films 517 (2009) 1750–1752 R.A. Hatton et al., Org. Electron. (2009), doi:10.1016/j.orgel.2008.12.013 Efficiency - Stability - Synthesis

  16. Stability test, experimental results • P3HT:PCBM 1 year lifetime out-door J.A. Hauch et al. Solar Energy Materials & Solar Cells 92 (2008) 727–731 Efficiency - Stability - Synthesis

  17. Methods to enhance stability • Protection from electrodes: slow down phase transition • Selection of Cathod material • An outlook: self-repair and defect-tolerating material J.Zhao, et al. J. Phys. Chem. B 2009, 113, 1587–1591 De Bettingnies, et.al. Synthetic Metals, 156 (2006) pp.510-513 DOE office of Science. “Basic Research Needs for Solar Energy Utilization”, Apr. (2005) Efficiency - Stability - Synthesis

  18. Synthesis methods • Wet processing • spin coating • repeatable • Screening printing • easy to define pattern • Good choice of solvent also increases efficiency www.brewerscience.com F.Krebs, Solar Energy Materials & Solar Cells 93 (2009) 465–475 S.E. Shaheen, et.al. Appl. Phys. Lett. 79, 2996 (2001) Maher Al-Ibrahim,et.al. Appl. Phys. Lett. 86,201120 (2005) Efficiency - Stability - Synthesis

  19. Summary • Main challenge to organic solar cells: efficiency • Morphology plays an important role. • Possible for low-cost mass-production • Additionally, there’re other advantages.

  20. References: [1] Cook et al. J. Phys. Chem. C, Vol. 113, No. 6, 2009 [2] Chapin et al. J.Appl.Phys.25 (1954) pp. 676 [3] Ashcroft et al. “Solid State Physics” ISBN: 7-5062-6631-8/O•482 pp.626-628 [4] Alferov, Nobel Lecture, Dec. 8, (2000) [5] Hoppe, et, al. J.Mater.Res., Vol.19, No.7, Jul (2004) [6] Christoph, et, al. Adv. Funct. Mater. 2001, 11, No. 5, October [7] Mayer, et,al. Materials today, Vol.10, No.11, Nov. (2007) pp.28-33 [8] P.D. Andersen et al., Opt. Mater. (2008), doi:10.1016/j.optmat.2008.11.014 [9] Y.Zhao,etal.,Sol.EnergyMater.Sol.Cells(2009),doi:10.1016/j.solmat.2008.12.007 [10] P. Vanlaeke et al. Solar Energy Materials & Solar Cells 90 (2006) 2150–2158 [11] F. Padinger, et al. Adv. Func. Mat. 13 (2003) 85. [12] X.Yang, et al. Nano Lett., Vol. 5, No. 4, 2005 [13] J.Zhao, et al. J. Phys. Chem. B 2009, 113, 1587–1591 [14] E.Johansson, et.al. J. Phys. Chem. C, 2009, 113 (7), 3014-3020 [15] J.Kang, et.al; Electrochemical and Solid-State Letters, 123 H64-H66 2009 [16] A. Colsmann et al. Thin Solid Films 517 (2009) 1750–1752 [17] R.A. Hatton et al., Org. Electron. (2009), doi:10.1016/j.orgel.2008.12.013 [18] J.A. Hauch et al. Solar Energy Materials & Solar Cells 92 (2008) 727–731 [19] De Bettingnies, et.al. Synthetic Metals, 156 (2006) pp.510-513 [20] DOE office of Science. “Basic Research Needs for Solar Energy Utilization”, Apr. (2005) [21] www.brewerscience.com [22] F.Krebs, Solar Energy Materials & Solar Cells 93 (2009) 465–475 [23] S.E. Shaheen, et.al. Appl. Phys. Lett. 79, 2996 (2001) [24] Maher Al-Ibrahim,et.al. Appl. Phys. Lett. 86,201120 (2005)

More Related