Novel device Substrates and Materials for Organic based Photovoltaics Frank Nüesch Laboratory for Functional Polymers Empa Materials Science and Technology Überlandstrasse 129 8600 Dübendorf SwissLaserNet, Basel, 25.6.2010 Materials Science & Technology
Big challenges in organic based PV NIR Materials Durability Processing Device structure Substrates and Encapsulation Materials Science & Technology SwissLaserNet, Basel, 25.6.2010 2
A (norm.) - 645-722 Squaraine dye synthesis 1.2 1.0 0.8 Dyes adsorbed on TiO 2 (Ethanol / Cheno) SQ01 (645 nm) SQ03 (650 nm) SQ02 (662 nm) SQ04 (672 nm) SQ06 (702 nm) BSQ01 (722 nm) Materials Science & Technology 0.6 0.4 0.2 0.0 Geiger T., Kuster S., Yum J. H., Moon S. J., Nazeeruddin M. K., Gratzel M., Nuesch SwissLaserNet, Basel, 25.6.2010 450 F., Adv. 500 Funct. 550 Mat., 2009, 600 2720-2727 650 700 750 800 3
absorbance irradiation density (W/m 2 nm) Cyanine dye synthesis silicon 1.5 solar emission 1.0 0.5 400 600 800 1000 1200 wavelength (nm) T. Geiger, H. Benmansour, B. Fan, R. Hany, F. Nüesch, Macromol. Rapid Commun, 2008, 29, 651-658 SwissLaserNet, Basel, 25.6.2010 4
The exciton diffusion length constraint + Pole Transp. electrode photon photon photon Electron Donor ~60 nm + Pole Transp. electrode Electron donor ~30 nm Electron acceptor Aluminum Electron acceptor Aluminum - Pole - Pole SwissLaserNet, Basel, 25.6.2010 5
Internal quantum efficiency close to unity e N ClO 4 - N+ CyC C 60 C 60 CyC 30 nm pristine doped 0.02 mol/mol NOBF 4 absorption Bilayer device Fan B., Castro F. A., Heier J., Hany R., Nuesch F., Org. Electron., 2010, 583-588 SwissLaserNet, Basel, 25.6.2010 6
Aggregation promotes charge collection? 1 m 1 m 1 m Hany R., Fan B., Castro F. A., Heier J., Kylberg W., Nuesch F., Prog. Photovoltaics Res. Appl., Submitted. J. Heier, R. Steiger, F. Nüesch, R. Hany, Langmuir 2010, doi: 10.1021/la903313k SwissLaserNet, Basel, 25.6.2010 7
Towards high performance bilayer cyanine solar cells Energy level matching PEDOT, η = 0.7 % PANI, η = 3 % Fan B., Castro F. A., Tsu-Te Chu B., Heier J., Opris D., Hany R., Nuesch F., J. Mater. Chem., 2010, 2952-2955 SwissLaserNet, Basel, 25.6.2010 8
Transparent, flexible precision fabric electrodes for OPV - Transparent flexible electrode to replace ITO on glass/pet - Polymer solar cells optimal for flexibility German Patent No. DE102008055969.5 Castro F. A., Chabrecek P., Hany R., Nuesch F., Phys. Status Solidi RRl, 2009, 3, 278 SwissLaserNet, Basel, 25.6.2010 9
Transmittance (%) Properties of fabric electrodes Sheet resistance PET-ITO: 40-80 Ω/ Fabric: 1-10 Ω/ 100 80 60 40 Fabric PET-ITO Al contact Active layer ~ 100-200 nm PEDOT:PSS ~ 100-1000 nm 20 0 400 600 800 1000 1200 Wavelength (nm) Fabric substrate Metal fibre Light Polymer fibres with polymer filling 100μm SwissLaserNet, Basel, 25.6.2010 10
Current density (ma/cm 2 ) Height ( m) Substrate smoothness Devices with Bulk heterojunction structure P3HT:PCBM blend (state-of-the-art) Profile 40 Metal fibre A B C Metal fibre 30 20 10 0 500 1000 1500 Length ( m) Critical area where short circuit could happen 15 Device I-V curves Al Blend PEDOT Fabric 10 5 0-5 -10 A B C -15-0.5 0.0 0.5 Voltage (V) SwissLaserNet, Basel, 25.6.2010 11
Laser-induced forward transfer using a photodynamic release layer Use of a UV-sensitive dynamic release layer Advantages : triazene polymer Dry transfer technique not limited by the solvent Three-dimensional structuring allowed Low thermal impact, debris-free ablation M. Nagel et al., Marcomol. Chem. Phys., 208 (2007), 277-286 Materials Science & Technology SwissLaserNet, Basel, 25.6.2010 12
OLED fabricated by the LIFT method ITO contact with Ag paste R. Fardel et al., Appl. Phys. Lett. 91, 061103 (2007) SwissLaserNet, Basel, 25.6.2010 13
Swiss PV platform ThinPV Workshop: A look inside solar cells, 16.11-18.11. 2008, Monte Verità, Ascona. For more details see conference announcement on our webpage: http://thinpv.empa.ch Conference in preparation to the CCEM project: Photovoltaics of the Future, 12.4.2005, Empa Dübendorf ThinPV Workshop: Thin Film PV - Needs and Desires from Industry, 5.10. 2007, Empa Dübendorf ThinPV Conference: Transparent Conducting Electrodes for Photovoltaics, Stade de Suiss, Bern, January 25 th in 2010. SwissLaserNet, Basel, 25.6.2010 14
Acknowledgements Empa (Dübendorf) Dr. William Kylberg Dr. Jakob Heier Dr. Hadjar Benmansour Dr. Fernando Castro PSI Prof. A. Wokaun Dr. T. Lippert ETHZ Physical & Colloid Chemistry (University of Utrecht) Dr. Jan Groenewold POLYMOL Fan Bin Dr. Roland Hany Dr. Matthias Nagel James Shaw-Stewart Dr. Romain Fardel Prof. D. Schlüter Sefar P. Chabrecek U. Sondenegger Materials Science & Technology Dr. D. Rentsch Simone Hochleitner Solaronix Marina Simeunovic Simon Kuster T. Meyer Dr. Thomas Geiger EPFL Prof. L. Zuppiroli Prof. M. Grätzel SwissLaserNet, Basel, 25.6.2010 15