Polymer bulk heterojunction solar cells employing Förster resonance energy transfer

There are two crucial tasks for realizing high-efficiency polymer solar cells (PSCs): increasing the range of the spectral absorption of light and efficiently harvesting photogenerated excitons. Here, we describe Forster resonance energy transfer-based heterojunction polymer solar cells that incorporate squaraine dye. The high absorbance of squaraine in the near-infrared region broadens the spectral absorption of the solar cells and assists in developing an ordered nanomorphology for enhanced charge transport. Femtosecond spectroscopic studies reveal highly efficient (up to 96%) excitation energy transfer from poly(3-hexylthiophene) to squaraine occurring on a picosecond timescale. We demonstrate a 38% increase in power conversion efficiency to reach 4.5%, and suggest that this system has improved exciton migration over long distances. This architecture transcends traditional multiblend systems, allowing multiple donor materials with separate spectral responses to work synergistically, thereby enabling an improvement in light absorption and conversion. This opens up a new avenue for the development of high-efficiency polymer solar cells.

[1]  Shijun Jia,et al.  Large-area organic photovoltaic module—Fabrication and performance , 2009 .

[2]  Luping Yu,et al.  Effects of additives on the morphology of solution phase aggregates formed by active layer components of high-efficiency organic solar cells. , 2011, Journal of the American Chemical Society.

[3]  C. Sheng,et al.  Experimental determination of the charge/neutral branching ratio η in the photoexcitation of π -conjugated polymers by broadband ultrafast spectroscopy , 2007 .

[4]  Thomas Kirchartz,et al.  Efficiency Limits of Organic Bulk Heterojunction Solar Cells , 2009 .

[5]  H. Ohkita,et al.  Selective Dye Loading at the Heterojunction in Polymer/Fullerene Solar Cells , 2011 .

[6]  Igor L. Medintz,et al.  Materials for fluorescence resonance energy transfer analysis: beyond traditional donor-acceptor combinations. , 2006, Angewandte Chemie.

[7]  Yang Yang,et al.  High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends , 2005 .

[8]  Wilhelm T S Huck,et al.  Enhanced photoresponse in solid-state excitonic solar cells via resonant energy transfer and cascaded charge transfer from a secondary absorber. , 2010, Nano letters.

[9]  Henry J. Snaith,et al.  The renaissance of dye-sensitized solar cells , 2012, Nature Photonics.

[10]  Martijn Lenes,et al.  Small Bandgap Polymers for Organic Solar Cells (Polymer Material Development in the Last 5 Years) , 2008 .

[11]  Kerry B. Burke,et al.  A study of the factors influencing the performance of ternary MEH-PPV:porphyrin:PCBM heterojunction devices: A steric approach to controlling charge recombination , 2011 .

[12]  F. Krebs,et al.  Low band gap polymers for organic photovoltaics , 2007 .

[13]  S. Forrest,et al.  Functionalized squaraine donors for nanocrystalline organic photovoltaics. , 2012, ACS nano.

[14]  Xiong Gong,et al.  Thermally Stable, Efficient Polymer Solar Cells with Nanoscale Control of the Interpenetrating Network Morphology , 2005 .

[15]  E. Thomas,et al.  Visualization of ordered spherical microdomains of block copolymers by phase contrast electron microscopy , 1984 .

[16]  Shinuk Cho,et al.  Effect of processing additive on the nanomorphology of a bulk heterojunction material. , 2010, Nano letters.

[17]  Tobin J. Marks,et al.  Efficient squaraine-based solution processable bulk-heterojunction solar cells. , 2008, Journal of the American Chemical Society.

[18]  Richard H Friend,et al.  Effect of annealing on P3HT:PCBM charge transfer and nanoscale morphology probed by ultrafast spectroscopy. , 2010, Nano letters.

[19]  W. You,et al.  Parallel-like bulk heterojunction polymer solar cells. , 2012, Journal of the American Chemical Society.

[20]  Jing-Shun Huang,et al.  Efficient and Air-Stable Polymer Photovoltaic Devices With $\hbox{WO}_{3}$–$\hbox{V}_{2}\hbox{O}_{5}$ Mixed Oxides as Anodic Modification , 2010, IEEE Electron Device Letters.

[21]  Q. Gong,et al.  Femtosecond Time-Resolved Fluorescence Study of P3HT/PCBM Blend Films , 2010 .

[22]  Donal D. C. Bradley,et al.  A strong regioregularity effect in self-organizing conjugated polymer films and high-efficiency polythiophene:fullerene solar cells , 2006 .

[23]  Christoph J. Brabec,et al.  Performance Enhancement of the P3HT/PCBM Solar Cells through NIR Sensitization Using a Small‐Bandgap Polymer , 2012 .

[24]  K. Ho,et al.  Materials for the active layer of organic photovoltaics: ternary solar cell approach. , 2013, ChemSusChem.

[25]  W. Belcher,et al.  The effect of porphyrin inclusion on the spectral response of ternary P3HT:porphyrin:PCBM bulk heterojunction solar cells , 2007 .

[26]  L. Pu,et al.  Search for Squaraine Derivatives That Can Be Sublimed without Thermal Decomposition , 2002 .

[27]  F. Krebs,et al.  A roll-to-roll process to flexible polymer solar cells: model studies, manufacture and operational stability studies , 2009 .

[28]  Trisha L. Andrew,et al.  Improving the performance of P3HT-fullerene solar cells with side-chain-functionalized poly(thiophene) additives: a new paradigm for polymer design. , 2012, ACS nano.

[29]  K. Ho,et al.  Monitoring the 3D nanostructures of bulk heterojunction polymer solar cells using confocal lifetime imaging. , 2010, Analytical chemistry.

[30]  Neil C Greenham,et al.  Polymer solar cells , 2013, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[31]  Craig A Grimes,et al.  Visible to near-infrared light harvesting in TiO2 nanotube array-P3HT based heterojunction solar cells. , 2009, Nano letters.

[32]  Jin Young Kim,et al.  Processing additives for improved efficiency from bulk heterojunction solar cells. , 2008, Journal of the American Chemical Society.

[33]  Nelson E. Coates,et al.  Bulk heterojunction solar cells with internal quantum efficiency approaching 100 , 2009 .

[34]  Maik Bärenklau,et al.  P3HT/PCBM Bulk Heterojunction Solar Cells: Impact of Blend Composition and 3D Morphology on Device Performance , 2010 .

[35]  Ole Hagemann,et al.  A complete process for production of flexible large area polymer solar cells entirely using screen printing—First public demonstration , 2009 .

[36]  J. Lakowicz.  Principles of fluorescence spectroscopy , 1983 .

[37]  Robert P. H. Chang,et al.  p-Type semiconducting nickel oxide as an efficiency-enhancing anode interfacial layer in polymer bulk-heterojunction solar cells , 2008, Proceedings of the National Academy of Sciences.

[38]  Craig A Grimes,et al.  High-efficiency Förster resonance energy transfer in solid-state dye sensitized solar cells. , 2010, Nano letters.

[39]  Christoph J. Brabec,et al.  Near IR Sensitization of Organic Bulk Heterojunction Solar Cells: Towards Optimization of the Spectral Response of Organic Solar Cells , 2010 .

[40]  A. Heeger,et al.  The Role of Processing in the Fabrication and Optimization of Plastic Solar Cells , 2009 .

[41]  Jean M. J. Fréchet,et al.  Increased light harvesting in dye-sensitized solar cells with energy relay dyes , 2009 .

[42]  M. Grätzel,et al.  High excitation transfer efficiency from energy relay dyes in dye-sensitized solar cells. , 2010, Nano letters.